{"title":"Black Friday - ZWO Filters","description":"\u003cp\u003eYear-end pricing on ZWO LRGB, 7nm narrowband, duo-band, UV\/IR-cut filters and protective windows.\u003c\/p\u003e","products":[{"product_id":"zwo-ir-cut-filter","title":"ZWO 1.25\" UV\/IR Cut Filter","description":"\u003ch2\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp\u003eThe \u003cstrong\u003eZWO 1.25\" UV\/IR Cut Filter\u003c\/strong\u003e is a simple but important imaging accessory for colour astronomy cameras, especially cameras with an AR protect window rather than a built-in UV\/IR blocking window. It blocks ultraviolet and infrared light from reaching the camera sensor, helping produce sharper, cleaner visible-light images.\u003c\/p\u003e\n\u003cp\u003eSilicon camera sensors are sensitive beyond the visible spectrum, including infrared. Since most telescope optics are not designed to bring infrared light to the same focus as visible light, unwanted IR can soften stars and reduce image sharpness. A UV\/IR cut filter helps keep the recorded image focused on the visible spectrum.\u003c\/p\u003e\n\u003ch2\u003e\u003cstrong\u003eWho Is This Product Best For?\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp\u003eThis filter is best for astrophotographers using colour CMOS or CCD cameras that need UV\/IR blocking for sharper broadband imaging. It is especially useful with ZWO colour cameras that have an AR protect window instead of an integrated IR-cut window.\u003c\/p\u003e\n\u003ch2\u003e\u003cstrong\u003eWhy Choose This Product?\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSharper colour-camera images:\u003c\/strong\u003e Blocks out-of-focus infrared light that can soften stars and fine detail.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProtects downstream filters:\u003c\/strong\u003e ZWO notes it can help protect expensive H-alpha filters from infrared radiation during solar-related setups.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e1.25\" threaded format:\u003c\/strong\u003e Fits common 1.25\" astronomy filter holders, filter wheels, and accessory threads.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProtective case included:\u003c\/strong\u003e The vendor lists a protective plastic case with the filter.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eBroadband colour astrophotography\u003c\/li\u003e\n\u003cli\u003ePlanetary imaging with colour cameras\u003c\/li\u003e\n\u003cli\u003eLunar imaging\u003c\/li\u003e\n\u003cli\u003eVisible-light imaging through telescopes that do not focus IR cleanly\u003c\/li\u003e\n\u003cli\u003eColour cameras with AR protect windows\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003e\u003cstrong\u003eCompatibility and Accessory Notes\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp\u003eThis listing is for the \u003cstrong\u003e1.25\" ZWO UV\/IR Cut Filter\u003c\/strong\u003e. ZWO also offers a 2\" version as a separate size. The 1.25\" version is suitable for common 1.25\" filter cells, filter wheels, and imaging accessories where the optical path accepts 1.25\" mounted filters.\u003c\/p\u003e\n\u003ch2\u003e\u003cstrong\u003eImportant Limitations\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eNot a narrowband filter:\u003c\/strong\u003e This is a UV\/IR blocking filter, not an H-alpha, OIII, SII, or light-pollution filter.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUse the correct size:\u003c\/strong\u003e Choose the 1.25\" or 2\" version based on your camera, filter wheel, filter drawer, and optical train.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNot needed for every camera:\u003c\/strong\u003e Some cameras already include UV\/IR blocking glass. Check your camera window before adding another filter.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h2\u003e\n\u003ch3\u003e\u003cstrong\u003eWhat does this filter block?\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eIt blocks ultraviolet and infrared light so the camera records primarily the visible spectrum.\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eWhy do colour astronomy cameras need a UV\/IR cut filter?\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eMany sensors are sensitive to infrared light. If that infrared light reaches the sensor, stars and fine detail can appear softer because the telescope may not focus IR at the same point as visible light.\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eDoes it come with a case?\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eYes. ZWO lists a protective plastic case with the 1.25\" filter.\u003c\/p\u003e\n\u003ch2\u003e\u003cstrong\u003eOur Recommendation\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp\u003eOntario Telescope recommends the ZWO 1.25\" UV\/IR Cut Filter for colour-camera imaging setups that need clean visible-light capture and sharper star profiles. It is a small accessory that can make a noticeable difference when your camera or optical train does not already include effective UV\/IR blocking.\u003c\/p\u003e","brand":"ZWO","offers":[{"title":"Default Title","offer_id":44013050593391,"sku":"IR-CUT","price":37.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/ir-uv-cut-filter-astronomy-460x460__87936.jpg?v=1766548483"},{"product_id":"zwo-ir-850nm-filter","title":"ZWO 1.25\" IR 850nm Pass Filter","description":"\u003ch2\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h2\u003e\u003cp\u003eThe \u003cstrong\u003eZWO 1.25\" IR 850nm Pass Filter\u003c\/strong\u003e is an infrared-pass astronomy filter for lunar and planetary imaging. It allows infrared light above approximately 850nm to pass while reducing the visible-light portion of the spectrum that is most affected by atmospheric seeing.\u003c\/p\u003e\u003cp\u003eWhen used with a monochrome camera or a colour camera that is sensitive to infrared, an 850nm IR-pass filter can help improve image steadiness and contrast during less-than-ideal seeing conditions. It can also be useful when imaging the Moon or planets at lower altitude, where atmospheric turbulence is more noticeable.\u003c\/p\u003e\u003ch2\u003e\u003cstrong\u003eWho Is This Product Best For?\u003c\/strong\u003e\u003c\/h2\u003e\u003cp\u003eThis filter is best for planetary and lunar imagers using IR-sensitive astronomy cameras. It is useful for imagers who want to capture steadier detail when visible-light seeing conditions are poor.\u003c\/p\u003e\u003ch2\u003e\u003cstrong\u003eWhy Choose This Product?\u003c\/strong\u003e\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e850nm IR-pass performance:\u003c\/strong\u003e Passes infrared light above approximately 850nm for specialized lunar and planetary imaging.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHelps with poor seeing:\u003c\/strong\u003e Longer infrared wavelengths are less affected by atmospheric turbulence than shorter visible wavelengths.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUseful near the horizon:\u003c\/strong\u003e Can help when imaging planets or the Moon at lower elevations.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e1.25\" format:\u003c\/strong\u003e Fits common 1.25\" filter holders, filter wheels, and planetary-camera accessories.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003ePlanetary imaging\u003c\/li\u003e\n\u003cli\u003eLunar imaging\u003c\/li\u003e\n\u003cli\u003eInfrared imaging with IR-sensitive cameras\u003c\/li\u003e\n\u003cli\u003eHigh-resolution imaging during poor seeing\u003c\/li\u003e\n\u003cli\u003eImaging targets at lower altitude\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003e\u003cstrong\u003eCompatibility and Accessory Notes\u003c\/strong\u003e\u003c\/h2\u003e\u003cp\u003eThis listing is for the \u003cstrong\u003e1.25\" ZWO IR 850nm Pass Filter\u003c\/strong\u003e. It should be used with a camera that has useful sensitivity at 850nm. Some colour cameras and many monochrome planetary cameras can record infrared wavelengths, but performance depends on the camera sensor and optical setup.\u003c\/p\u003e\u003ch2\u003e\u003cstrong\u003eImportant Limitations\u003c\/strong\u003e\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eNot a UV\/IR cut filter:\u003c\/strong\u003e This filter passes infrared light; it does not block IR for visible-light colour imaging.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCamera sensitivity matters:\u003c\/strong\u003e The camera must be sensitive at approximately 850nm for this filter to be effective.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpecialized use:\u003c\/strong\u003e This is mainly for lunar, planetary, and infrared imaging, not general deep-sky colour imaging.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h2\u003e\u003ch3\u003e\u003cstrong\u003eWhat does an IR 850nm pass filter do?\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eIt allows infrared wavelengths above approximately 850nm to pass while reducing shorter visible wavelengths.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eWhy use this filter for planets?\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eInfrared wavelengths are less disturbed by atmospheric seeing, so an IR-pass filter can help produce steadier planetary detail when conditions are not ideal.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eCan I use this with a colour camera?\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eYes, if the colour camera is sensitive to infrared. The result will not be standard full-colour imaging; this is a specialized infrared imaging filter.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eIs this the same as a UV\/IR cut filter?\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eNo. A UV\/IR cut filter blocks infrared for visible-light imaging. This IR 850nm filter passes infrared for specialized imaging.\u003c\/p\u003e\u003ch2\u003e\u003cstrong\u003eOur Recommendation\u003c\/strong\u003e\u003c\/h2\u003e\u003cp\u003eOntario Telescope recommends the ZWO 1.25\" IR 850nm Pass Filter for lunar and planetary imagers who want a specialized tool for improving detail in challenging seeing conditions with IR-sensitive cameras.\u003c\/p\u003e","brand":"ZWO","offers":[{"title":"Default Title","offer_id":44013052625007,"sku":"IR-850","price":37.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/ir850-filter-planets-moon-460x460__42969.jpg?v=1766548492"},{"product_id":"zwo-lrgb-filters-new-version","title":"ZWO LRGB Filters - New version","description":"\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" line-height:=\"\" background-color:=\"\"\u003eThe new  ZWO RGBL Filters  are designed to approximately equalize the flux of ASI1600 mono sensor\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" line-height:=\"\" background-color:=\"\"\u003eBetter transmission, Better coating,  Better color separation\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" line-height:=\"\" background-color:=\"\"\u003ethe RGB color combine weights will be approximately 1:1:1\u003c\/p\u003e\u003cul style=\"margin: 0px 0px 20px 17px; padding: 0px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" line-height:=\"\" background-color:=\"\"\u003e\n\u003cli\u003eFine-optically polished to ensure accurate 1\/4 wavefront\u003c\/li\u003e\n\u003cli\u003emore than 92% transmission at passband\u003c\/li\u003e\n\u003cli\u003eInfrared wavelength 700-1100nm cut-off\u003c\/li\u003e\n\u003cli\u003ePrecision off-band blocking\u003c\/li\u003e\n\u003cli\u003eMulti-layers anti-reflection coating\u003c\/li\u003e\n\u003cli\u003eSmall spectral  gap  to minimize effect of light pollution\u003c\/li\u003e\n\u003cli\u003eMore parfocal   thickness 1.9+\/-0.03 mm\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"ZWO","offers":[{"title":"Default Title","offer_id":44013341966447,"sku":"ZWO-LRGB-1","price":188.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/NEW-LRGB1-460x460__73175.jpg?v=1766550826"},{"product_id":"zwo-narrowband-1-25-filter","title":"ZWO narrowband 1.25 filter","description":"\u003ch2 style=\"position: relative; padding: 0px 0px 10px; line-height: 28px; color: rgb(238, 57, 57); margin: 0px; font-size: 20px; font-family: \" pt sans narrow sans-serif rgb normal background-color:=\"\" font-weight:=\"\"\u003eProduct Description\u003c\/h2\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eNarrowband filter do not eliminate the effects of light pollution or increase the object s brightness. In many cases, they increase the contrast between nebula and night sky, not brightening the nebula.\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eIt can reduce the transmission of certain wavelengths of light, specifically those produced by artificial light including mercury vapor, and both high and low pressure sodium vapor lights and the unwanted natural light caused by neutral oxygen emission in our atmosphere (i.e. skyglow).\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eThe ZWO  H-Alpha filter  has a bandpass of  7nm and passes light at 656nm  wavelength, light transmission rate comes up to 80%. Best choice of narrowband H-alpha astrophotography filter for high-contrast imaging and revealing rich details of the nebula even in areas with strong light pollution, just prepare to experience the infinite fun with it !\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003e\u003ca href=\"https:\/\/astronomy-imaging-camera.com\/wp-content\/uploads\/1.25Ha.jpg\" style=\"background: transparent; color: rgb(238, 57, 57);\"\u003e\u003cimg class=\"alignnone size-large wp-image-4500\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/1.25Ha-1024x1024_6af26116-6ca5-400e-9a2c-872e8639bcd5.jpg?v=1766551095\" alt=\"1-25ha\" width=\"1024\" height=\"1024\" style=\"border: 0px; max-width: 100%; height: auto; display: block;\"\u003e\u003c\/a\u003e\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eThe ZWO narrowband S-II 7nm filter passes light at 672nm wavelength with a bandpass of 7nm which is designed for nebula observation . It is suitable for visual observation on most emission nebulae, planetary nebulae and supernova remnants, use it with H-alpha and OIII narrowband filters (SHO Set) for tricolor CCD astrophotography.\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003e \u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003e\u003ca href=\"https:\/\/astronomy-imaging-camera.com\/wp-content\/uploads\/1.25SII.jpg\" style=\"background: transparent; color: rgb(238, 57, 57);\"\u003e\u003cimg class=\"alignnone size-large wp-image-4501\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/1.25SII-1024x1024_7e7b866f-bfc9-4799-9c7b-825784902c8b.jpg?v=1766551097\" alt=\"1-25sii\" width=\"1024\" height=\"1024\" style=\"border: 0px; max-width: 100%; height: auto; display: block;\"\u003e\u003c\/a\u003e\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eThe ZWO nrrowband O-III 7nm filter is designed for nebula observation allowing 7nm bandwidth of light centered on a wavelength of 500nm through,  which corresponds to OIII emission lines, blocking out all other light.  Adding the ZWO O-III Narrowband filter to your imaging collection will help you go beyond the RGB imaging and will help capture your favorite nebulas in a totally new light, no matter how polluted your skies may be!\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003e\u003ca href=\"https:\/\/astronomy-imaging-camera.com\/wp-content\/uploads\/1.25OIII1.jpg\" style=\"background: transparent; color: rgb(238, 57, 57);\"\u003e\u003cimg class=\"alignnone size-large wp-image-4503\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/1.25OIII1-1024x1024_31ffc02d-3294-4750-8239-b456cd576fd8.jpg?v=1766551098\" alt=\"1-25oiii1\" width=\"1024\" height=\"1024\" style=\"border: 0px; max-width: 100%; height: auto; display: block;\"\u003e\u003c\/a\u003e\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003e\u003cstrong\u003eTechnical Data\u003c\/strong\u003e\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eFWHM 7±0.5nm\u003cbr\u003eThickness 1.9+\/-0.03 mm  (1.25 \/31mm\/36mm)\u003cbr\u003eFine-optically polished to ensure accurate 1\/4 wavefront  over the both surfaces\u003cbr\u003e80% transmission at H-alpha line 656nm (H-Alpha filter )\u003cbr\u003e80% transmission at SII line 672nm (SII filter )\u003cbr\u003e80% transmission at major OIII line 500nm (OIII filter )\u003c\/p\u003e","brand":"ZWO","offers":[{"title":"Default Title","offer_id":44013362053231,"sku":"1.25\" NB set","price":468.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/125-SET11-460x460__02852.jpg?v=1766551100"},{"product_id":"zwo-lrgb-36mm-filters","title":"ZWO LRGB 36mm Filters","description":"\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eThe ZWO LRGB  36mm filter has better transmission, better coating,  better color separation\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003ethe RGB color combine weights will be approximately 1:1:1\u003c\/p\u003e\u003cul style=\"margin: 0px 0px 20px 17px; padding: 0px; list-style-position: initial; list-style-image: initial; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003e\n\u003cli\u003eFine-optically polished to ensure accurate 1\/4 wavefront\u003c\/li\u003e\n\u003cli\u003emore than 92% transmission at passband\u003c\/li\u003e\n\u003cli\u003eInfrared wavelength 700-1100nm cut-off\u003c\/li\u003e\n\u003cli\u003ePrecision off-band blocking\u003c\/li\u003e\n\u003cli\u003eMulti-layers anti-reflection coating\u003c\/li\u003e\n\u003cli\u003eSmall spectral  gap  to minimize effect of light pollution\u003c\/li\u003e\n\u003cli\u003eMore parfocal   thickness  2mm\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003ehere are the detailed photo\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/36MM-L_a51c70e9-0a97-44eb-b16d-bfdfbafb4bc7.jpg?v=1766551616\" style=\"background: transparent; color: rgb(238, 57, 57);\"\u003e\u003cimg class=\"alignnone size-full wp-image-4588\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/36MM-L_a51c70e9-0a97-44eb-b16d-bfdfbafb4bc7.jpg?v=1766551616\" alt=\"36mm-l\" width=\"600\" height=\"600\" style=\"border: 0px; max-width: 100%; height: auto; display: block;\"\u003e\u003c\/a\u003e\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003e \u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/36mm-R_b2e3dc27-907f-4f8d-952b-2bfcf44a01e8.jpg?v=1766551617\" style=\"background: transparent; color: rgb(238, 57, 57);\"\u003e\u003cimg class=\"alignnone size-full wp-image-4569\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/36mm-R_b2e3dc27-907f-4f8d-952b-2bfcf44a01e8.jpg?v=1766551617\" alt=\"36mm-r\" width=\"600\" height=\"600\" style=\"border: 0px; max-width: 100%; height: auto; display: block;\"\u003e\u003c\/a\u003e\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/36mm-G_625800a2-33f3-4d68-8fa1-7118a48a747c.jpg?v=1766551619\" style=\"background: transparent; color: rgb(238, 57, 57);\"\u003e\u003cimg class=\"alignnone size-full wp-image-4568\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/36mm-G_625800a2-33f3-4d68-8fa1-7118a48a747c.jpg?v=1766551619\" alt=\"36mm-g\" width=\"600\" height=\"600\" style=\"border: 0px; max-width: 100%; height: auto; display: block;\"\u003e\u003c\/a\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/36MM-B_130bf950-b30e-4f3e-bd73-f5188f2ede06.jpg?v=1766551621\" style=\"background: transparent; color: rgb(238, 57, 57);\"\u003e\u003cimg class=\"alignnone size-full wp-image-4570\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/36MM-B_130bf950-b30e-4f3e-bd73-f5188f2ede06.jpg?v=1766551621\" alt=\"36mm-b\" width=\"600\" height=\"600\" style=\"border: 0px; max-width: 100%; height: auto; display: block;\"\u003e\u003c\/a\u003e\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003ehere is the the transmission curve\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/RGBL-ASI1600_45d8420b-91b2-453f-a584-337adfb27b6b.jpg?v=1766551623\" style=\"background: transparent; color: rgb(238, 57, 57);\"\u003e\u003cimg class=\"alignnone size-full wp-image-3734\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/RGBL-ASI1600_45d8420b-91b2-453f-a584-337adfb27b6b.jpg?v=1766551623\" alt=\"RGBL ASI1600\" width=\"958\" height=\"686\" style=\"border: 0px; max-width: 100%; height: auto; display: block;\"\u003e\u003c\/a\u003e\u003c\/p\u003e","brand":"ZWO","offers":[{"title":"Default Title","offer_id":44013369786479,"sku":"LRGB-36","price":252.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/36mm-LRGB-460x460__34168.jpg?v=1766551625"},{"product_id":"zwo-ir-cut-filter-2","title":"ZWO 2\" UV\/IR Cut Filter","description":"\u003ch2\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h2\u003e\u003cp\u003eThe \u003cstrong\u003eZWO 2\" UV\/IR Cut Filter\u003c\/strong\u003e is a full-size astronomy imaging filter designed to block ultraviolet and infrared light from reaching your camera sensor. It is useful with colour astronomy cameras that use an AR protect window rather than built-in UV\/IR blocking glass.\u003c\/p\u003e\u003cp\u003eMany astronomy camera sensors remain sensitive to infrared light. Since most telescope optics do not focus infrared at exactly the same point as visible light, unblocked IR can soften star profiles and reduce image sharpness. A UV\/IR cut filter helps keep the recorded image focused on the visible spectrum.\u003c\/p\u003e\u003ch2\u003e\u003cstrong\u003eWho Is This Product Best For?\u003c\/strong\u003e\u003c\/h2\u003e\u003cp\u003eThis filter is best for astrophotographers using 2\" filter drawers, filter wheels, adapters, or larger imaging trains where a 1.25\" filter would be too small.\u003c\/p\u003e\u003ch2\u003e\u003cstrong\u003eWhy Choose This Product?\u003c\/strong\u003e\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e2\" imaging format:\u003c\/strong\u003e Better suited to larger sensors and optical trains than a 1.25\" filter.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eVisible-light sharpening:\u003c\/strong\u003e Blocks out-of-focus ultraviolet and infrared light that can soften images.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eM48 thread:\u003c\/strong\u003e ZWO lists the 2\" version with an M48×0.75 male thread.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSimple optical upgrade:\u003c\/strong\u003e Helps colour cameras produce cleaner visible-light images.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eBroadband colour astrophotography\u003c\/li\u003e\n\u003cli\u003eLunar imaging\u003c\/li\u003e\n\u003cli\u003ePlanetary imaging with colour cameras\u003c\/li\u003e\n\u003cli\u003eVisible-light telescope imaging\u003c\/li\u003e\n\u003cli\u003e2\" filter drawers, filter wheels, and M48-threaded imaging trains\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003e\u003cstrong\u003eCompatibility and Accessory Notes\u003c\/strong\u003e\u003c\/h2\u003e\u003cp\u003eThis listing is for the \u003cstrong\u003e2\" ZWO UV\/IR Cut Filter\u003c\/strong\u003e. ZWO lists the 2\" version with a 5mm body plus 2mm thread thickness and an M48×0.75 male thread. Choose this version when your imaging train requires 2\" mounted filters or when using a larger sensor where a smaller 1.25\" filter could vignette.\u003c\/p\u003e\u003ch2\u003e\u003cstrong\u003eImportant Limitations\u003c\/strong\u003e\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eNot a narrowband filter:\u003c\/strong\u003e This is a UV\/IR blocking filter, not an H-alpha, OIII, SII, dual-band, or light-pollution filter.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSize matters:\u003c\/strong\u003e Use the 2\" version only if your accessory train accepts 2\" \/ M48-threaded mounted filters.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCamera-dependent need:\u003c\/strong\u003e Some cameras already include UV\/IR blocking glass, so check your camera window before stacking filters.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h2\u003e\u003ch3\u003e\u003cstrong\u003eWhat does this filter block?\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eIt blocks ultraviolet and infrared light, allowing your camera to record primarily visible light.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eWhy use the 2\" version instead of 1.25\"?\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThe 2\" version is better suited to larger sensors and imaging trains where a 1.25\" filter may restrict the light path.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eWhat thread does the 2\" version use?\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eZWO lists the 2\" version with an M48×0.75 male thread.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eIs this a light-pollution filter?\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eNo. It is a UV\/IR cut filter for visible-light imaging, not a light-pollution reduction filter.\u003c\/p\u003e\u003ch2\u003e\u003cstrong\u003eOur Recommendation\u003c\/strong\u003e\u003c\/h2\u003e\u003cp\u003eOntario Telescope recommends the ZWO 2\" UV\/IR Cut Filter for larger colour-camera imaging setups that need clean visible-light capture, reduced star bloat, and compatibility with 2\" or M48-threaded imaging accessories.\u003c\/p\u003e","brand":"ZWO","offers":[{"title":"Default Title","offer_id":44013370572911,"sku":"IR-CUT-2","price":62.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/2IRCUT-600X600__57863.jpg?v=1766551715"},{"product_id":"zwo-2-lrgb-filters","title":"ZWO 2\" LRGB Filters","description":"\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eThe new  ZWO 2? LRGB Filters has good performance in transmission, also it has good coating,  good color separation.\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003e\u003cstrong\u003eTechnical Parameter:\u003c\/strong\u003e\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eName: ZWO 2? LRGB Filters  (4 filters)\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eSize: 2?\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eThickness: 5 mm+2.5mm(thread)\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eThread: M48*0.75\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eThickness: 1.85mm\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003e\u003ca href=\"https:\/\/astronomy-imaging-camera.com\/wp-content\/uploads\/filter-threads.png\" style=\"background: transparent; color: rgb(238, 57, 57);\"\u003e\u003cbr\u003e\u003c\/a\u003e\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eThe RGB color combine weights will be approximately 1:1:1\u003c\/p\u003e\u003cul style=\"margin: 0px 0px 20px 17px; padding: 0px; list-style-position: initial; list-style-image: initial; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003e\n\u003cli\u003eFine-optically polished to ensure accurate 1\/4 wavefront\u003c\/li\u003e\n\u003cli\u003emore than 92% transmission at passband\u003c\/li\u003e\n\u003cli\u003eInfrared wavelength 700-1100nm cut-off\u003c\/li\u003e\n\u003cli\u003ePrecision off-band blocking\u003c\/li\u003e\n\u003cli\u003eMulti-layers anti-reflection coating\u003c\/li\u003e\n\u003cli\u003eSmall spectral “gap” to minimize effect of light pollution\u003c\/li\u003e\n\u003cli\u003eMore parfocal – thickness 1.9+\/-0.03 mm\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"ZWO","offers":[{"title":"Default Title","offer_id":44013544636527,"sku":"ZWO-LRGB2","price":379.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/2-LRGB-ZWO__44151.jpg?v=1766555968"},{"product_id":"zwo-duo-band-filter-1-25","title":"ZWO Duo-Band Filter 1.25\"","description":"\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eZWO Duo-Band Filter is a dual narrowband filter primarily aimed at complementing our range of colour ASI cameras. The Duo-Band filter is aimed at the astronomer who may already own a One Shot Colour (OSC) camera and wants to image using narrowband techniques or emission objects without purchasing a mono camera, filter wheel and narrowband filter set.\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eThe Duo-Band filter offers an economical entry into the world of narrowband imaging and can also offer a practical solution to imaging in light polluted urban areas.\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eThe dual band pass nature of the Duo-Band filter passes light at Ha (656nm) and OIII (500nm) wavelength, and can reduce the interference from natural light sources such as moonlight, or artificial light pollution such as street lighting.\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eIt can help improve the contrast and visibility of deep sky objects such as emission nebula using a OSC camera.\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eIf you are looking for a solution to deep sky photography in light pollution area, then ZWO Duo-Band Filter will be a great choice.\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eThe Duo-Band filter can be used with all ASI cameras and EFW Electronic Filter Wheel and comes in 1.25” and 2” sizes.\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eSize: Standard 1.25”\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eGlass thickness: 1.85 mm\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eBandwidth: HA (15nm) OIII (35nm)\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eSurface quality: 60\/40 (Refer to MIL-O-13830)\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eSchott substrate material\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eMore than 90% transmission at major OIII line 486.nm1, 496nm and 501nm.\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eMore than 80% transmission at Ha line 656.3nm\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eThe incoming light transmitted through the filter should be perpendicular to the filter, or the incident angle should be less than 8°. Therefore, this product is not suitable for wide-angle or ultra wide-angle lenses.\u003ca href=\"https:\/\/astronomy-imaging-camera.com\/wp-content\/uploads\/5.png\" style=\"background: transparent; color: rgb(238, 57, 57);\"\u003e\u003cbr\u003e\u003c\/a\u003e\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/incident-light-to-the-filter_d6aea5e9-1adb-4450-98df-5f5a79884f8e.png?v=1766555981\" style=\"background: transparent; color: rgb(238, 57, 57);\"\u003e\u003cimg class=\"aligncenter size-full wp-image-16682\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/incident-light-to-the-filter_d6aea5e9-1adb-4450-98df-5f5a79884f8e.png?v=1766555981\" alt=\"incident-light-to-the-filter\" width=\"645\" height=\"274\" style=\"border: 0px; display: block; text-align: center; margin: auto; height: auto; max-width: 100%; padding: 0px; background: none;\"\u003e\u003c\/a\u003e\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003e \u003c\/p\u003e\u003ch2 style=\"position: relative; padding: 0px 0px 10px; line-height: 28px; color: rgb(238, 57, 57); margin: 0px; font-size: 20px; font-family: \" pt sans narrow sans-serif rgb normal background-color:=\"\" font-weight:=\"\"\u003e\u003cspan style=\"color: rgb(255, 0, 0);\"\u003eTest Results\u003c\/span\u003e\u003c\/h2\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eImages captured with ASI color cameras and Duo-Band Filters. You can see that the potential for deep space photography in strong light polluted areas is vastly improved with the Duo-Band filters.\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb center font-size:=\"\" background-color:=\"\" text-align:=\"\"\u003e\u003ca href=\"https:\/\/astronomy-imaging-camera.com\/wp-content\/uploads\/%E4%BF%AE%E6%94%B9%EF%BC%883%EF%BC%891.jpg\" style=\"background: transparent; color: rgb(238, 57, 57);\"\u003e\u003cimg class=\"alignnone size-large wp-image-17435\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/E4_BF_AE_E6_94_B9_EF_BC_883_EF_BC_891-947x1024_b3793829-3bc8-4c5d-986a-616a6cd9164a.jpg?v=1766555983\" alt=\"??(3)(1)\" width=\"947\" height=\"1024\" style=\"border: 0px; max-width: 100%; height: auto; display: block;\"\u003e\u003c\/a\u003e\u003ca href=\"https:\/\/astronomy-imaging-camera.com\/wp-content\/uploads\/Heartwith-without-Duo-Filter1.jpg\" style=\"background: transparent; color: rgb(238, 57, 57);\"\u003e\u003cimg class=\"alignnone wp-image-17409\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/Heartwith-without-Duo-Filter1-1024x348_56bed510-5211-4d06-be4a-ab3b41c60a55.jpg?v=1766555984\" alt=\"Heart(with without)-Duo-Filter(1)\" width=\"1124\" height=\"382\" style=\"border: 0px; max-width: 100%; height: auto; display: block;\"\u003e\u003c\/a\u003e\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb center font-size:=\"\" background-color:=\"\" text-align:=\"\"\u003e\u003ca href=\"https:\/\/astronomy-imaging-camera.com\/wp-content\/uploads\/%E4%BF%AE%E6%94%B9%EF%BC%881%EF%BC%892.jpg\" style=\"background: transparent; color: rgb(238, 57, 57);\"\u003e\u003cimg class=\"alignnone size-large wp-image-17426\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/E4_BF_AE_E6_94_B9_EF_BC_881_EF_BC_892-947x1024_aed539c2-7d79-4afc-9ade-68edc51e142c.jpg?v=1766555986\" alt=\"??(1)(2)\" width=\"947\" height=\"1024\" style=\"border: 0px; max-width: 100%; height: auto; display: block;\"\u003e\u003c\/a\u003e\u003ca href=\"https:\/\/astronomy-imaging-camera.com\/wp-content\/uploads\/Horsehead-with-without-Filter1.jpg\" style=\"background: transparent; color: rgb(238, 57, 57);\"\u003e\u003cimg class=\"alignnone size-large wp-image-17411\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/Horsehead-with-without-Filter1-1024x671_7acfae2e-dc32-4fe7-a761-4ecd5894da5e.jpg?v=1766555988\" alt=\"Horsehead-(with without)-Filter(1)\" width=\"1024\" height=\"671\" style=\"border: 0px; max-width: 100%; height: auto; display: block;\"\u003e\u003c\/a\u003e\u003c\/p\u003e","brand":"ZWO","offers":[{"title":"Default Title","offer_id":44013544734831,"sku":"ZWO-DB-1.25","price":125.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/ZWO-Duo-Band-Filter-460x460__72535.jpg?v=1766555990"},{"product_id":"zwo-duo-band-filter-2","title":"ZWO Duo-Band Filter 2\"","description":"\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eZWO Duo-Band Filter is a dual narrowband filter primarily aimed at complementing our range of colour ASI cameras. The Duo-Band filter is aimed at the astronomer who may already own a One Shot Colour (OSC) camera and wants to image using narrowband techniques or emission objects without purchasing a mono camera, filter wheel and narrowband filter set.\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eThe Duo-Band filter offers an economical entry into the world of narrowband imaging and can also offer a practical solution to imaging in light polluted urban areas.\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eThe dual band pass nature of the Duo-Band filter passes light at Ha (656nm) and OIII (500nm) wavelength, and can reduce the interference from natural light sources such as moonlight, or artificial light pollution such as street lighting.\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eIt can help improve the contrast and visibility of deep sky objects such as emission nebula using a OSC camera.\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eIf you are looking for a solution to deep sky photography in light pollution area, then ZWO Duo-Band Filter will be a great choice.\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eThe Duo-Band filter can be used with all ASI cameras and EFW Electronic Filter Wheel and comes in 1.25” and 2” sizes.\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eSize: Standard 2”\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eGlass thickness: 1.85 mm\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eBandwidth: HA (15nm) OIII (35nm)\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eSurface quality: 60\/40 (Refer to MIL-O-13830)\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eSchott substrate material\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eMore than 90% transmission at major OIII line 486.nm1, 496nm and 501nm.\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eMore than 80% transmission at Ha line 656.3nm\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eThe incoming light transmitted through the filter should be perpendicular to the filter, or the incident angle should be less than 8°. Therefore, this product is not suitable for wide-angle or ultra wide-angle lenses.\u003ca href=\"https:\/\/astronomy-imaging-camera.com\/wp-content\/uploads\/5.png\" style=\"background: transparent; color: rgb(238, 57, 57);\"\u003e\u003cbr\u003e\u003c\/a\u003e\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/incident-light-to-the-filter_3773c5aa-f002-4da3-a58b-7f85de937a22.png?v=1766555995\" style=\"background: transparent; color: rgb(238, 57, 57);\"\u003e\u003cimg class=\"aligncenter size-full wp-image-16682\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/incident-light-to-the-filter_3773c5aa-f002-4da3-a58b-7f85de937a22.png?v=1766555995\" alt=\"incident-light-to-the-filter\" width=\"645\" height=\"274\" style=\"border: 0px; display: block; text-align: center; margin: auto; height: auto; max-width: 100%; padding: 0px; background: none;\"\u003e\u003c\/a\u003e\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003e \u003c\/p\u003e\u003ch2 style=\"position: relative; padding: 0px 0px 10px; line-height: 28px; color: rgb(238, 57, 57); margin: 0px; font-size: 20px; font-family: \" pt sans narrow sans-serif rgb normal background-color:=\"\" font-weight:=\"\"\u003e\u003cspan style=\"color: rgb(255, 0, 0);\"\u003eTest Results\u003c\/span\u003e\u003c\/h2\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eImages captured with ASI color cameras and Duo-Band Filters. You can see that the potential for deep space photography in strong light polluted areas is vastly improved with the Duo-Band filters.\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb center font-size:=\"\" background-color:=\"\" text-align:=\"\"\u003e\u003ca href=\"https:\/\/astronomy-imaging-camera.com\/wp-content\/uploads\/%E4%BF%AE%E6%94%B9%EF%BC%883%EF%BC%891.jpg\" style=\"background: transparent; color: rgb(238, 57, 57);\"\u003e\u003cimg class=\"alignnone size-large wp-image-17435\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/E4_BF_AE_E6_94_B9_EF_BC_883_EF_BC_891-947x1024_626b2682-aeeb-4189-8ef0-86adb1021193.jpg?v=1766555996\" alt=\"??(3)(1)\" width=\"947\" height=\"1024\" style=\"border: 0px; max-width: 100%; height: auto; display: block;\"\u003e\u003c\/a\u003e\u003ca href=\"https:\/\/astronomy-imaging-camera.com\/wp-content\/uploads\/Heartwith-without-Duo-Filter1.jpg\" style=\"background: transparent; color: rgb(238, 57, 57);\"\u003e\u003cimg class=\"alignnone wp-image-17409\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/Heartwith-without-Duo-Filter1-1024x348_eb3ba235-0757-4867-91f3-b0312ddff1b4.jpg?v=1766555998\" alt=\"Heart(with without)-Duo-Filter(1)\" width=\"1124\" height=\"382\" style=\"border: 0px; max-width: 100%; height: auto; display: block;\"\u003e\u003c\/a\u003e\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb center font-size:=\"\" background-color:=\"\" text-align:=\"\"\u003e\u003ca href=\"https:\/\/astronomy-imaging-camera.com\/wp-content\/uploads\/%E4%BF%AE%E6%94%B9%EF%BC%881%EF%BC%892.jpg\" style=\"background: transparent; color: rgb(238, 57, 57);\"\u003e\u003cimg class=\"alignnone size-large wp-image-17426\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/E4_BF_AE_E6_94_B9_EF_BC_881_EF_BC_892-947x1024_4aa8c44b-0ed3-4a7f-825b-70a68b1aa166.jpg?v=1766555999\" alt=\"??(1)(2)\" width=\"947\" height=\"1024\" style=\"border: 0px; max-width: 100%; height: auto; display: block;\"\u003e\u003c\/a\u003e\u003ca href=\"https:\/\/astronomy-imaging-camera.com\/wp-content\/uploads\/Horsehead-with-without-Filter1.jpg\" style=\"background: transparent; color: rgb(238, 57, 57);\"\u003e\u003cimg class=\"alignnone size-large wp-image-17411\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/Horsehead-with-without-Filter1-1024x671_dea20f09-d029-40e4-bd12-6815f8c2f799.jpg?v=1766556001\" alt=\"Horsehead-(with without)-Filter(1)\" width=\"1024\" height=\"671\" style=\"border: 0px; max-width: 100%; height: auto; display: block;\"\u003e\u003c\/a\u003e\u003c\/p\u003e","brand":"ZWO","offers":[{"title":"Default Title","offer_id":44013545029743,"sku":"ZWO-DB2","price":214.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/ZWO-Duo-Band-Filter-460x460__14069.jpg?v=1766556003"},{"product_id":"zwo-new-narrowband-36mm-filter","title":"ZWO New narrowband 36mm filter","description":"\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eNarrowband filter do not eliminate the effects of light pollution or increase the object’s brightness. In many cases, they increase the contrast between nebula and night sky, not brightening the nebula.\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eIt can reduce the transmission of certain wavelengths of light, specifically those produced by artificial light including mercury vapor, and both high and low pressure sodium vapor lights and the unwanted natural light caused by neutral oxygen emission in our atmosphere (i.e. skyglow).\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003e\u003cem\u003eForm 2018, ZWO Made a progress on narrowband filters with new standard, provide better performance.\u003c\/em\u003e\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003e\u003cstrong\u003eTechnical Parameter:\u003c\/strong\u003e\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eName: ZWO New narrowband  36mm filter\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eSize: D=36mm\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eThickness: 2mm\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eThe ZWO  H-Alpha filter  has a bandpass of  7nm and passes light at 656nm  wavelength, light transmission rate comes up to 80%. Best choice of narrowband H-alpha astrophotography filter for high-contrast imaging and revealing rich details of the nebula even in areas with strong light pollution, just prepare to experience the infinite fun with it !\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003e \u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/36mm-Ha600_951a6cd8-3860-4669-93e3-0df15616ed9e.jpg?v=1766560378\" style=\"background: transparent; color: rgb(238, 57, 57);\"\u003e\u003cimg class=\"alignnone size-full wp-image-4497\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/36mm-Ha600_951a6cd8-3860-4669-93e3-0df15616ed9e.jpg?v=1766560378\" alt=\"36mm-ha600\" width=\"600\" height=\"600\" style=\"border: 0px; max-width: 100%; height: auto; display: block;\"\u003e\u003c\/a\u003e\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eThe ZWO narrowband S-II 7nm filter passes light at 672nm wavelength with a bandpass of 7nm which is designed for nebula observation . It is suitable for visual observation on most emission nebulae, planetary nebulae and supernova remnants, use it with H-alpha and OIII narrowband filters (SHO Set) for tricolor CCD astrophotography.\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003e \u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/36mm-SII600_1ca03eb8-8c2f-4f65-bb3d-088b50cebab6.jpg?v=1766560379\" style=\"background: transparent; color: rgb(238, 57, 57);\"\u003e\u003cimg class=\"alignnone size-full wp-image-4499\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/36mm-SII600_1ca03eb8-8c2f-4f65-bb3d-088b50cebab6.jpg?v=1766560379\" alt=\"36mm-sii600\" width=\"600\" height=\"600\" style=\"border: 0px; max-width: 100%; height: auto; display: block;\"\u003e\u003c\/a\u003e\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eThe ZWO nrrowband O-III 7nm filter is designed for nebula observation allowing 7nm bandwidth of light centered on a wavelength of 500nm through,  which corresponds to OIII emission lines, blocking out all other light.  Adding the ZWO O-III Narrowband filter to your imaging collection will help you go beyond the RGB imaging and will help capture your favorite nebulas in a totally new light, no matter how polluted your skies may be!\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003e \u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/36mm-OIII600_8d09ed2b-948c-4aee-b187-52c92060e3ce.jpg?v=1766560381\" style=\"background: transparent; color: rgb(238, 57, 57);\"\u003e\u003cimg class=\"alignnone size-full wp-image-4498\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/36mm-OIII600_8d09ed2b-948c-4aee-b187-52c92060e3ce.jpg?v=1766560381\" alt=\"36mm-oiii600\" width=\"600\" height=\"600\" style=\"border: 0px; max-width: 100%; height: auto; display: block;\"\u003e\u003c\/a\u003e\u003c\/p\u003e\u003cul style=\"margin: 0px 0px 20px 17px; padding: 0px; list-style-position: initial; list-style-image: initial; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003e\n\u003cli\u003eHubble look of images can be made by the combination of H-alpha, OIII-CCD and SII-CCD, such as the famous “Pillars of Creation” (M16 Eagle Nebula)\u003c\/li\u003e\n\u003cli\u003eNarrowband imaging with SHO set (H-alpha, OIII-CCD and SII-CCD) can be done with the moon up in heavy light pollution, so your equipment is not sitting dormant for several weeks\u003c\/li\u003e\n\u003c\/ul\u003e\u003cul style=\"margin: 0px 0px 20px 17px; padding: 0px; list-style-position: initial; list-style-image: initial; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003e\u003cli\u003eH-alpha filter is the first narrowband addition to LRGB set for most imagers who blend a black-and-white Ha image into RGB data to enhance structural detail while maintaining natural look\u003c\/li\u003e\u003c\/ul\u003e\u003ch3 style=\"position: relative; padding: 0px 0px 10px; line-height: 28px; color: rgb(238, 57, 57); margin: 0px; font-size: 20px; font-family: \" pt sans narrow sans-serif rgb normal background-color:=\"\" font-weight:=\"\"\u003e\u003c\/h3\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003e \u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003e\u003cstrong\u003eNew OIII filter:\u003c\/strong\u003e\u003c\/p\u003e\u003cp style=\"margin: 0px; zoom: 1; padding: 0px 0px 16px; color: rgb(32, 32, 32); font-family: \" pt sans sans-serif rgb font-size:=\"\" background-color:=\"\"\u003eBoth side will be fine.\u003c\/p\u003e","brand":"ZWO","offers":[{"title":"Default Title","offer_id":44013713555567,"sku":"ZWO-36mm-NB","price":608.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/new-36mm-SET600-460x460__74283.jpg?v=1766560384"},{"product_id":"zwo-d21-uv-ir-cut-protective-window","title":"ZWO D21 UV IR-Cut Protective Window","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThe \u003cstrong\u003eZWO D21 UV IR-Cut Protective Window\u003c\/strong\u003e is a \u003cstrong\u003e21 mm\u003c\/strong\u003e replacement window for ZWO ASI cameras. It is \u003cstrong\u003e1.1 mm\u003c\/strong\u003e thick, figured to \u003cstrong\u003e1\/4 λ flatness\u003c\/strong\u003e, and sits directly in front of the sensor, where it does two jobs at once: it seals the sensor chamber against dust and humidity, and it blocks ultraviolet and infrared light outside the visible band.\u003c\/p\u003e\n\u003cp\u003eThis is a consumable spare, not an upgrade. If the window on your camera is scratched, fogged, or contaminated beyond cleaning, this is the part that replaces it.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThis is a good match if you own a ZWO camera that shipped with a \u003cstrong\u003eD21 × 1.1 mm UV IR-cut window\u003c\/strong\u003e — the ASI120MC-S or ASI178MC — and need to replace a damaged one.\u003c\/p\u003e\n\u003cp\u003eIt is also the correct part if you own a camera fitted with a \u003cstrong\u003eD21 AR window\u003c\/strong\u003e and want to convert it to IR-cut, so that you no longer need a separate UV\/IR-cut filter in the imaging train. Confirm your camera's window diameter before ordering: a 21 mm window will not fit a body machined for 25 mm or 32 mm.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e21 mm diameter, 1.1 mm thick:\u003c\/strong\u003e the D21 form factor used across ZWO's smaller-sensor bodies\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUV IR-cut coating:\u003c\/strong\u003e passes visible light and rejects ultraviolet and infrared, unlike an AR window, which passes both\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e1\/4 λ flatness:\u003c\/strong\u003e the window sits in a converging beam directly ahead of the sensor, so surface figure matters — a poorly figured window degrades star shapes\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDust and humidity seal:\u003c\/strong\u003e the window is the sensor chamber's only physical barrier\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eOptical glass with coatings on both faces\u003c\/strong\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eReplacing a scratched or contaminated window\u003c\/strong\u003e on an ASI120MC-S or ASI178MC\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eConverting a D21 AR-equipped camera to IR-cut\u003c\/strong\u003e, removing the need for a separate UV\/IR-cut filter\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePlanetary and lunar imaging with refractors\u003c\/strong\u003e, where uncorrected infrared focuses at a different point than visible light and softens the image\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDaytime or terrestrial use\u003c\/strong\u003e of an ASI camera, where infrared leakage shifts colour badly\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eCompatibility and Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eCameras shipped with this window:\u003c\/strong\u003e ASI120MC-S and ASI178MC\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDiameter is not interchangeable:\u003c\/strong\u003e D21 fits 21 mm bodies only. ASI174-series bodies take the D25; ASI1600 \/ ASI294 \/ ASI183 take the D32; ASI6200 \/ ASI2400 \/ ASI2600 take the D60\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAR vs IR-cut:\u003c\/strong\u003e an AR window is anti-reflective only and does not cut UV or IR. If your camera came with a D21 AR window and you want IR-cut behaviour at the sensor, this is the part that changes it\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNo installation direction:\u003c\/strong\u003e ZWO confirms the window has no preferred orientation — it can be fitted either face forward\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eReplacement procedure:\u003c\/strong\u003e ZWO publishes an official guide, \u003ca href=\"https:\/\/i.zwoastro.com\/wp-content\/uploads\/2025\/12\/c36da643469647ac8334179b49aa8b11.pdf\" target=\"_blank\" rel=\"noopener\"\u003eHow to Replace the Camera Protective Window\u003c\/a\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMechanical part only\u003c\/strong\u003e — no electronic function, no camera communication\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eImportant Limitations\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eThis is a bare optical window, not a filter you can thread into an imaging train.\u003c\/strong\u003e It only works installed inside the camera body\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eReplacement means opening the sensor chamber.\u003c\/strong\u003e Dust introduced during the swap lands on or near the sensor. Work in still, clean air. ZWO does not recommend that users replace windows on cameras where the window is factory-fitted at close tolerance\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNot a substitute for a light-pollution or narrowband filter\u003c\/strong\u003e — it cuts UV and IR only\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFits 21 mm bodies only.\u003c\/strong\u003e Check your camera model against the list above before ordering\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSold as a single window.\u003c\/strong\u003e No tools, gaskets, or retaining ring included\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eWhich cameras use the D21 UV IR-cut window?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eZWO ships this window on the ASI120MC-S and ASI178MC. It also physically fits other D21-bodied cameras that came with an AR window, if you want to convert them to IR-cut.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat is the difference between the AR window and the UV IR-cut window?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe AR window is anti-reflective coated but optically clear — it passes ultraviolet and infrared straight through to the sensor. The UV IR-cut window blocks both. ZWO states plainly that the AR window does not cut UV.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDo I still need a UV\/IR-cut filter in my imaging train?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNot for that purpose, no. With this window installed, the IR-cut function happens at the sensor. That frees the filter drawer or wheel for something else.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDoes the window have to face a particular direction?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNo. ZWO confirms there is no specific installation direction.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eMy protective window is scratched. Do I need to replace it?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eA scratched window scatters light and can produce halos around bright stars. The camera will still focus and operate without it, but the sensor is then exposed to dust and humidity — which is a far worse problem. Replace it.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWill this fit my ASI1600 or ASI294?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNo. Those bodies use the 32 mm D32 window. This is 21 mm.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eIs there a D32 UV IR-cut version?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNo. ZWO produces the D32 in AR only. If you need IR-cut on an ASI1600 or ASI294, use a filter in the imaging train instead.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eIs this good for beginners?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe part is simple, but fitting it is not a beginner task — it means opening the sensor chamber. If you are not confident doing that cleanly, have it done rather than risk dust on the sensor.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eIn short: a 21 mm × 1.1 mm UV IR-cut window at 1\/4 λ flatness — the correct replacement for an ASI120MC-S or ASI178MC, and the part that converts a D21 AR-equipped camera to IR-cut at the sensor. Confirm your diameter first; D21 does not fit D25, D32, or D60 bodies.\u003c\/p\u003e","brand":"ZWO","offers":[{"title":"Default Title","offer_id":53804401000559,"sku":"D21IR-CUT","price":24.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/426474105bc9afcb1261044235a281b3-1.jpg?v=1784083160"},{"product_id":"zwo-d21-ar-protective-window","title":"ZWO D21 AR Protective Window","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThe \u003cstrong\u003eZWO D21 AR Protective Window\u003c\/strong\u003e is a \u003cstrong\u003e21 mm\u003c\/strong\u003e replacement window for ZWO ASI cameras. It is \u003cstrong\u003e1.1 mm\u003c\/strong\u003e thick, figured to \u003cstrong\u003e1\/4 λ flatness\u003c\/strong\u003e, and carries an \u003cstrong\u003eanti-reflective coating on both faces\u003c\/strong\u003e. It sits directly in front of the sensor and seals the sensor chamber against dust and humidity.\u003c\/p\u003e\n\u003cp\u003eAn AR window is optically clear. It does \u003cstrong\u003enot\u003c\/strong\u003e block ultraviolet or infrared — it only reduces surface reflections. That distinction matters, and it is covered below.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThis is a good match if you own a ZWO camera that shipped with a \u003cstrong\u003eD21 × 1.1 mm AR window\u003c\/strong\u003e and need to replace one that is scratched, fogged, or contaminated beyond cleaning.\u003c\/p\u003e\n\u003cp\u003eIt is also the right choice if you run your \u003cstrong\u003eUV\/IR-cut filtering in the imaging train\u003c\/strong\u003e — in a filter drawer, wheel, or threaded filter — and want the window at the sensor to stay optically neutral rather than cutting the band a second time.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e21 mm diameter, 1.1 mm thick:\u003c\/strong\u003e the D21 form factor used across ZWO's smaller-sensor bodies\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAnti-reflective coating:\u003c\/strong\u003e reduces reflection losses and internal glare at the window surfaces, which is where halos around bright stars can originate\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOptically clear:\u003c\/strong\u003e passes UV and IR straight through — all wavelength control happens elsewhere in your train\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e1\/4 λ flatness:\u003c\/strong\u003e the window sits in a converging beam immediately ahead of the sensor, so surface figure directly affects star shapes\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDust and humidity seal:\u003c\/strong\u003e the window is the sensor chamber's only physical barrier\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eReplacing a scratched or contaminated AR window\u003c\/strong\u003e on a D21-bodied ASI camera\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMonochrome imaging\u003c\/strong\u003e, where filtering is handled by a filter wheel and a sensor-side IR-cut would be redundant\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNarrowband and photometric work\u003c\/strong\u003e, where you want no unnecessary coatings shaping the passband\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInfrared and methane-band planetary imaging\u003c\/strong\u003e, which an IR-cut window would defeat outright\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eCompatibility and Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMatch models:\u003c\/strong\u003e ASI120 series, ASI178 series, ASI290 series, ASI224MC series, ASI385 series, ASI185MC series, ASI220 series, ASI462 series, ASI662 series, ASI678 series, ASI664 series, and ASI715 series\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDiameter is not interchangeable:\u003c\/strong\u003e D21 fits 21 mm bodies only. ASI174-series bodies take the D25; ASI1600 \/ ASI294 \/ ASI183 \/ ASI533 take the D32; ASI6200 \/ ASI2400 \/ ASI2600 take the D60\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWant IR-cut instead?\u003c\/strong\u003e Fit the D21 UV IR-Cut window in the same body — same diameter and thickness, different coating\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNo installation direction:\u003c\/strong\u003e ZWO confirms the window has no preferred orientation\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eReplacement procedure:\u003c\/strong\u003e see ZWO's official guide, \u003ca href=\"https:\/\/i.zwoastro.com\/wp-content\/uploads\/2025\/12\/c36da643469647ac8334179b49aa8b11.pdf\" target=\"_blank\" rel=\"noopener\"\u003eHow to Replace the Camera Protective Window\u003c\/a\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMechanical part only\u003c\/strong\u003e — no electronic function, no camera communication\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eImportant Limitations\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eThis window does not cut UV or IR.\u003c\/strong\u003e ZWO states that plainly. If you are imaging in colour through a refractor with no filter in the train, infrared will focus at a different point than visible light and soften your image. Use the D21 UV IR-Cut window instead, or add a filter\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNot a threaded filter.\u003c\/strong\u003e It is a bare optical window that only works installed inside the camera body\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eReplacement means opening the sensor chamber.\u003c\/strong\u003e Dust introduced during the swap lands on or near the sensor. ZWO specifically advises against user replacement on some bodies — including the ASI462MC\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFits 21 mm bodies only.\u003c\/strong\u003e Check your camera against the list above before ordering\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSold as a single window.\u003c\/strong\u003e No tools, gaskets, or retaining ring included\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eWhat is the difference between the AR window and the UV IR-cut window?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe AR window is anti-reflective coated but optically clear — it passes ultraviolet and infrared through to the sensor. The UV IR-cut window blocks both. ZWO confirms directly that the AR window does not cut UV.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhich cameras use the D21 AR window?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe ASI120, ASI178, ASI290, ASI224MC, ASI385, ASI185MC, ASI220, ASI462, ASI662, ASI678, ASI664, and ASI715 series.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eShould I choose AR or IR-cut?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eIf you already filter in the imaging train — a filter wheel, drawer, or threaded UV\/IR-cut — keep the AR window and let those do the work. If you shoot one-shot-colour with nothing in the train, the IR-cut window does the job at the sensor and frees your drawer for something else.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDoes the window have to face a particular direction?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNo. ZWO confirms there is no specific installation direction, so the anti-reflective coating works either way round.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan I fit this to my ASI462MC myself?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eIt is the correct window for that camera, but ZWO does not recommend replacing it yourself. Their guidance, not ours.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eMy protective window is scratched — can I just remove it?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe camera will focus and operate without it, but the sensor is then open to dust and humidity, which is a far worse problem than the scratch. Replace it.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWill this fit my ASI1600 or ASI294?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNo. Those bodies use the 32 mm D32 AR window. This is 21 mm.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eIs this good for beginners?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe part is simple; fitting it is not a beginner task, since it means opening the sensor chamber. If you are not confident working clean, have it done.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eIn short: a 21 mm × 1.1 mm anti-reflective window at 1\/4 λ flatness — the correct spare for D21-bodied ASI cameras, and the right choice when your UV\/IR filtering already happens in the imaging train. It does not cut UV or IR; if you need that at the sensor, fit the D21 UV IR-Cut instead.\u003c\/p\u003e","brand":"ZWO","offers":[{"title":"Default Title","offer_id":53804443926639,"sku":"D21AR","price":24.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/f8fc754efe2799ca917eee21d7350efd.jpg?v=1784083457"},{"product_id":"zwo-d25-uv-ir-cut-protective-window","title":"ZWO D25 UV IR-Cut Protective Window","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThe \u003cstrong\u003eZWO D25 UV IR-Cut Protective Window\u003c\/strong\u003e is a \u003cstrong\u003e25 mm\u003c\/strong\u003e replacement window for ZWO ASI cameras. It is \u003cstrong\u003e1.1 mm\u003c\/strong\u003e thick, figured to \u003cstrong\u003e1\/4 λ flatness\u003c\/strong\u003e, and mounts directly in front of the sensor. It seals the sensor chamber against dust and humidity while blocking ultraviolet and infrared outside the visible band.\u003c\/p\u003e\n\u003cp\u003eThis is a consumable spare and a conversion part, not an upgrade to image quality on its own.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThis is a good match if you own an \u003cstrong\u003eASI174-series camera\u003c\/strong\u003e — ASI174MM, ASI174MC, ASI174MM-COOL, or ASI174MC-COOL — and need to replace a scratched or contaminated window.\u003c\/p\u003e\n\u003cp\u003eIt is also the part ZWO specifies if you own an \u003cstrong\u003eASI485MC\u003c\/strong\u003e, which ships with the D25 AR window, and want to convert it to IR-cut at the sensor rather than carrying a UV\/IR-cut filter in the imaging train.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e25 mm diameter, 1.1 mm thick:\u003c\/strong\u003e the D25 form factor used on ASI174-series and ASI485MC bodies\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUV IR-cut coating:\u003c\/strong\u003e passes visible light and rejects ultraviolet and infrared, unlike the AR window, which passes both\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e1\/4 λ flatness:\u003c\/strong\u003e the window sits in a converging beam directly ahead of the sensor, so surface figure feeds straight into star shapes\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDust and humidity seal:\u003c\/strong\u003e the window is the sensor chamber's only physical barrier\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCoated optical glass\u003c\/strong\u003e, supplied as a bare window\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eReplacing a scratched or contaminated window\u003c\/strong\u003e on any ASI174-series camera\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eConverting an ASI485MC from AR to IR-cut\u003c\/strong\u003e, which is ZWO's own stated use for this part\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePlanetary and lunar imaging through refractors\u003c\/strong\u003e, where uncorrected infrared focuses at a different point than visible light and softens detail\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOne-shot-colour imaging with no filter in the train\u003c\/strong\u003e, where infrared leakage shifts colour and bloats stars\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eCompatibility and Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eCameras shipped with this window:\u003c\/strong\u003e ASI174MM, ASI174MC, ASI174MM-COOL, and ASI174MC-COOL\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eASI485MC conversion:\u003c\/strong\u003e the ASI485MC ships with the D25 AR window; ZWO names the D25IR-CUT as the correct IR-cut replacement for it\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDiameter is not interchangeable:\u003c\/strong\u003e D25 fits 25 mm bodies only. Smaller planetary bodies take the D21; ASI1600 \/ ASI294 \/ ASI183 \/ ASI533 take the D32; ASI6200 \/ ASI2400 \/ ASI2600 take the D60\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNo installation direction:\u003c\/strong\u003e ZWO confirms the window has no preferred orientation\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eReplacement procedure:\u003c\/strong\u003e see ZWO's official guide, \u003ca href=\"https:\/\/i.zwoastro.com\/wp-content\/uploads\/2025\/12\/c36da643469647ac8334179b49aa8b11.pdf\" target=\"_blank\" rel=\"noopener\"\u003eHow to Replace the Camera Protective Window\u003c\/a\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMechanical part only\u003c\/strong\u003e — no electronic function, no camera communication\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eImportant Limitations\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eThis is a bare optical window, not a threaded filter.\u003c\/strong\u003e It only works installed inside the camera body\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eReplacement means opening the sensor chamber.\u003c\/strong\u003e Dust introduced during the swap lands on or near the sensor — work in still, clean air\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIt will defeat infrared imaging.\u003c\/strong\u003e If you shoot IR-pass or methane-band planetary work, this window blocks exactly the light you want. Use the D25 AR instead\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNot a light-pollution or narrowband filter\u003c\/strong\u003e — it cuts UV and IR only\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFits 25 mm bodies only.\u003c\/strong\u003e Check your camera against the list above before ordering\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSold as a single window.\u003c\/strong\u003e No tools, gaskets, or retaining ring included\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eWhich cameras use the D25 UV IR-cut window?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eZWO fits it to the ASI174MM, ASI174MC, ASI174MM-COOL, and ASI174MC-COOL. It is also the specified IR-cut conversion window for the ASI485MC.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eI have an ASI485MC — is this the right part?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eYes, if you want IR-cut at the sensor. The ASI485MC ships with the D25 AR window, and ZWO names the D25IR-CUT as its IR-cut replacement.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat is the difference between the AR window and the UV IR-cut window?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe AR window is anti-reflective coated but optically clear and passes UV and IR. This one blocks both. ZWO confirms the AR window does not cut UV.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDo I still need a UV\/IR-cut filter in my imaging train?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNot for that purpose. With this window installed the IR-cut happens at the sensor, which frees a filter drawer or wheel slot.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDoes the window have to face a particular direction?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNo. ZWO confirms there is no specific installation direction.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan I still do infrared planetary imaging with this fitted?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNo — that is the one thing it rules out. An IR-pass or methane-band filter needs infrared to reach the sensor, and this window stops it. Keep or fit the D25 AR for that work.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWill this fit my ASI1600 or ASI294?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNo. Those bodies use the 32 mm D32 window. This is 25 mm.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eIs this good for beginners?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe part is simple, but fitting it means opening the sensor chamber. If you are not confident working clean, have it done rather than risk dust on the sensor.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eIn short: a 25 mm × 1.1 mm UV IR-cut window at 1\/4 λ flatness — the correct spare for the ASI174 series and ZWO's specified IR-cut conversion for the ASI485MC. It rules out infrared imaging by design; if you need that, use the D25 AR.\u003c\/p\u003e","brand":"ZWO","offers":[{"title":"Default Title","offer_id":53804450873455,"sku":"D25IR-CUT","price":24.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/426474105bc9afcb1261044235a281b3-1_3793fb17-3951-4b93-b19c-b63bda49cfac.jpg?v=1784083502"},{"product_id":"zwo-d25-ar-protective-window","title":"ZWO D25 AR Protective Window","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThe \u003cstrong\u003eZWO D25 AR Protective Window\u003c\/strong\u003e is a \u003cstrong\u003e25 mm\u003c\/strong\u003e replacement window for ZWO ASI cameras. It is \u003cstrong\u003e1.1 mm\u003c\/strong\u003e thick, figured to \u003cstrong\u003e1\/4 λ flatness\u003c\/strong\u003e, and carries an \u003cstrong\u003eanti-reflective coating\u003c\/strong\u003e. It sits directly in front of the sensor and seals the sensor chamber against dust and humidity.\u003c\/p\u003e\n\u003cp\u003eAn AR window is optically clear. It reduces surface reflections but does \u003cstrong\u003enot\u003c\/strong\u003e block ultraviolet or infrared — that distinction drives most of the buying decision here, and it is covered below.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThis is a good match if you own an \u003cstrong\u003eASI174-series camera\u003c\/strong\u003e or an \u003cstrong\u003eASI485MC\u003c\/strong\u003e — both ship with the D25 AR window — and need to replace one that is scratched, fogged, or contaminated beyond cleaning.\u003c\/p\u003e\n\u003cp\u003eIt is also the right choice if you \u003cstrong\u003efilter in the imaging train\u003c\/strong\u003e rather than at the sensor, or if you do \u003cstrong\u003einfrared work\u003c\/strong\u003e that an IR-cut window would defeat outright.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e25 mm diameter, 1.1 mm thick:\u003c\/strong\u003e the D25 form factor used on ASI174-series and ASI485MC bodies\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAnti-reflective coating:\u003c\/strong\u003e reduces reflection losses and internal glare at the window surfaces, a common origin of halos around bright stars\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOptically clear:\u003c\/strong\u003e passes UV and IR straight through — all wavelength control happens elsewhere\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e1\/4 λ flatness:\u003c\/strong\u003e the window sits in a converging beam directly ahead of the sensor, so surface figure directly affects star shapes\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDust and humidity seal:\u003c\/strong\u003e the window is the sensor chamber's only physical barrier\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eReplacing a scratched or contaminated AR window\u003c\/strong\u003e on an ASI174-series camera or ASI485MC\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInfrared and methane-band planetary imaging\u003c\/strong\u003e, which requires infrared to reach the sensor\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMonochrome imaging\u003c\/strong\u003e where a filter wheel already handles wavelength selection\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNarrowband and photometric work\u003c\/strong\u003e, where you want no unnecessary coating shaping the passband\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHigh-frame-rate solar and lunar work\u003c\/strong\u003e with the ASI174, where the sensor's speed is the point and filtering is external\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eCompatibility and Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMatch models:\u003c\/strong\u003e the ASI174 series. The ASI485MC also ships with this window\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWant IR-cut instead?\u003c\/strong\u003e Fit the D25 UV IR-Cut window — same diameter and thickness, different coating. ZWO names it specifically as the ASI485MC's IR-cut conversion\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDiameter is not interchangeable:\u003c\/strong\u003e D25 fits 25 mm bodies only. Smaller planetary bodies take the D21; ASI1600 \/ ASI294 \/ ASI183 \/ ASI533 take the D32; ASI6200 \/ ASI2400 \/ ASI2600 take the D60\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNo installation direction:\u003c\/strong\u003e ZWO confirms the window has no preferred orientation, so the coating works either way round\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eReplacement procedure:\u003c\/strong\u003e see ZWO's official guide, \u003ca href=\"https:\/\/i.zwoastro.com\/wp-content\/uploads\/2025\/12\/c36da643469647ac8334179b49aa8b11.pdf\" target=\"_blank\" rel=\"noopener\"\u003eHow to Replace the Camera Protective Window\u003c\/a\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMechanical part only\u003c\/strong\u003e — no electronic function, no camera communication\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eImportant Limitations\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eThis window does not cut UV or IR.\u003c\/strong\u003e ZWO states that plainly. Shooting one-shot-colour through a refractor with nothing in the train means infrared focuses at a different point than visible light and softens the image. Use the D25 UV IR-Cut instead, or filter in the train\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNot a threaded filter.\u003c\/strong\u003e It is a bare optical window that only works installed inside the camera body\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eReplacement means opening the sensor chamber.\u003c\/strong\u003e Dust introduced during the swap lands on or near the sensor — work in still, clean air\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFits 25 mm bodies only.\u003c\/strong\u003e Check your camera against the list above before ordering\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSold as a single window.\u003c\/strong\u003e No tools, gaskets, or retaining ring included\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eWhich cameras use the D25 AR window?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe ASI174 series. The ASI485MC also ships with it from the factory.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat is the difference between the AR window and the UV IR-cut window?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe AR window is anti-reflective coated but optically clear — it passes ultraviolet and infrared through to the sensor. The UV IR-cut window blocks both. ZWO confirms directly that the AR window does not cut UV.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eShould I choose AR or IR-cut?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eIf you filter in the imaging train, or you image in infrared, keep the AR window. If you shoot one-shot-colour with nothing in the train, the IR-cut version does that job at the sensor and frees a filter slot.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eI have an ASI485MC and want IR-cut — what do I order?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe D25IR-CUT. ZWO names it as the correct IR-cut replacement for that camera.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDoes the window have to face a particular direction?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNo. ZWO confirms there is no specific installation direction.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eMy protective window is scratched — can I just remove it?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe camera will focus and operate without it, but the sensor is then open to dust and humidity, which is a worse problem than the scratch. Replace it.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWill this fit my ASI1600 or ASI294?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNo. Those bodies use the 32 mm D32 AR window. This is 25 mm.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eIs this good for beginners?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe part is simple; fitting it is not, since it means opening the sensor chamber. If you are not confident working clean, have it done.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eIn short: a 25 mm × 1.1 mm anti-reflective window at 1\/4 λ flatness — the factory spare for the ASI174 series and ASI485MC, and the right choice when you filter in the train or image in infrared. It does not cut UV or IR; if you need that at the sensor, fit the D25 UV IR-Cut.\u003c\/p\u003e","brand":"ZWO","offers":[{"title":"Default Title","offer_id":53804457459823,"sku":"D25AR","price":24.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/f8fc754efe2799ca917eee21d7350efd_cd3116e0-c9d7-41b3-9269-843cf646dcc0.jpg?v=1784083547"},{"product_id":"zwo-d32-ar-protective-window","title":"ZWO D32 AR Protective Window","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThe \u003cstrong\u003eZWO D32 AR Protective Window\u003c\/strong\u003e is a \u003cstrong\u003e32 mm\u003c\/strong\u003e replacement window for ZWO ASI cameras. It is \u003cstrong\u003e2 mm\u003c\/strong\u003e thick — nearly double the 1.1 mm of the smaller D21 and D25 windows — figured to \u003cstrong\u003e1\/4 λ flatness\u003c\/strong\u003e, and carries an \u003cstrong\u003eanti-reflective coating\u003c\/strong\u003e. It sits directly in front of the sensor and seals the sensor chamber against dust and humidity.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eZWO produces the D32 in AR only.\u003c\/strong\u003e There is no D32 UV IR-cut window. If you need IR-cut on a D32-bodied camera, it has to happen in the imaging train — see the limitations below.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThis is a good match if you own a \u003cstrong\u003eD32-bodied ASI camera\u003c\/strong\u003e — the ASI1600, ASI294, ASI183, ASI533, ASI585, ASI990, or ASI991 series — and need to replace a window that is scratched, fogged, or contaminated beyond cleaning.\u003c\/p\u003e\n\u003cp\u003eBecause there is no IR-cut alternative in this diameter, this is simply \u003cstrong\u003ethe\u003c\/strong\u003e window for these bodies rather than a choice between two coatings.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e32 mm diameter, 2 mm thick:\u003c\/strong\u003e the D32 form factor, covering ZWO's 4\/3\" and 1\" class sensors\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAnti-reflective coating:\u003c\/strong\u003e reduces reflection losses and internal glare at the window surfaces, a common origin of halos around bright stars\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOptically clear:\u003c\/strong\u003e passes UV and IR straight through — all wavelength control happens in your imaging train\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e1\/4 λ flatness:\u003c\/strong\u003e the window sits in a converging beam directly ahead of the sensor, so surface figure feeds straight into star shapes\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e2 mm substrate:\u003c\/strong\u003e thicker glass than the D21 and D25 windows, matched to the larger clear aperture\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDust and humidity seal:\u003c\/strong\u003e the window is the sensor chamber's only physical barrier\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eReplacing a scratched or contaminated window\u003c\/strong\u003e on an ASI1600, ASI294, ASI183, ASI533, ASI585, ASI990, or ASI991\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMonochrome deep-sky imaging\u003c\/strong\u003e, where a filter wheel handles all wavelength selection anyway\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNarrowband imaging\u003c\/strong\u003e, where you want no extra coating shaping the passband\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInfrared and methane-band planetary imaging\u003c\/strong\u003e, which requires infrared to reach the sensor\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOne-shot-colour imaging\u003c\/strong\u003e with a UV\/IR-cut filter carried in a drawer, wheel, or threaded ahead of the camera\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eCompatibility and Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMatch models:\u003c\/strong\u003e ASI1600 series, ASI294 series, ASI183 series, ASI533 series, ASI585 series, ASI990 series, and ASI991 series\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eASI585 Air is not included\u003c\/strong\u003e in the D32 match list — ZWO calls that exception out specifically\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDiameter is not interchangeable:\u003c\/strong\u003e D32 fits 32 mm bodies only. Smaller planetary bodies take the D21 or D25; ASI6200 \/ ASI2400 \/ ASI2600 take the D60\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNo IR-cut option in this size.\u003c\/strong\u003e Carry a UV\/IR-cut filter in a ZWO filter drawer or filter wheel instead\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNo installation direction:\u003c\/strong\u003e ZWO confirms the window has no preferred orientation, so the coating works either way round\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eReplacement procedure:\u003c\/strong\u003e see ZWO's official guide, \u003ca href=\"https:\/\/i.zwoastro.com\/wp-content\/uploads\/2025\/12\/c36da643469647ac8334179b49aa8b11.pdf\" target=\"_blank\" rel=\"noopener\"\u003eHow to Replace the Camera Protective Window\u003c\/a\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMechanical part only\u003c\/strong\u003e — no electronic function, no camera communication\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eImportant Limitations\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eThis window does not cut UV or IR\u003c\/strong\u003e, and ZWO does not make a D32 that does. On a one-shot-colour camera behind a refractor with nothing in the train, infrared will focus at a different point than visible light and soften the image. Put a UV\/IR-cut filter in your train\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNot a threaded filter.\u003c\/strong\u003e It is a bare optical window that only works installed inside the camera body\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eReplacement means opening the sensor chamber.\u003c\/strong\u003e Dust introduced during the swap lands on or near the sensor — work in still, clean air\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFits 32 mm bodies only\u003c\/strong\u003e, and not the ASI585 Air. Check your camera against the list above before ordering\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSold as a single window.\u003c\/strong\u003e No tools, gaskets, or retaining ring included\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eWhich cameras use the D32 AR window?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe ASI1600, ASI294, ASI183, ASI533, ASI585, ASI990, and ASI991 series. The ASI585 Air is excluded.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eIs there a D32 UV IR-cut window?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNo. ZWO makes the D32 in AR only. If you need IR-cut on one of these cameras, use a UV\/IR-cut filter in a filter drawer or wheel ahead of the camera.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhy is this window 2 mm thick when the D21 and D25 are 1.1 mm?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe larger clear aperture needs a thicker substrate to hold its figure. Keeping 1\/4 λ flatness across 32 mm takes more glass than across 21 mm.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDoes the window have to face a particular direction?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNo. ZWO confirms there is no specific installation direction.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eMy ASI1600 window is scratched — can I just leave it out?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe camera will focus and operate without it, but the sensor chamber is then open to dust and humidity, which is a far worse problem than the scratch. Replace it.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eI have an ASI585 Air. Does this fit?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNo. ZWO excludes the ASI585 Air from the D32 match list even though other ASI585-series bodies are included. Check before ordering.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWill this fit my ASI2600 or ASI6200?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNo. Those bodies use the 60 mm D60 window. This is 32 mm.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eIs this good for beginners?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe part is simple; fitting it is not, since it means opening the sensor chamber. If you are not confident working clean, have it done rather than risk dust on the sensor.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eIn short: a 32 mm × 2 mm anti-reflective window at 1\/4 λ flatness — the only protective window ZWO makes for the ASI1600, ASI294, ASI183, ASI533 and ASI585 bodies. There is no IR-cut version in this diameter, so plan on a UV\/IR-cut filter in your train if you shoot one-shot-colour.\u003c\/p\u003e","brand":"ZWO","offers":[{"title":"Default Title","offer_id":53804465782895,"sku":"D32-2-AR","price":37.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/f8fc754efe2799ca917eee21d7350efd_560cc259-2914-4c06-9428-4b4114c23ba7.jpg?v=1784083596"},{"product_id":"zwo-d60-uv-ir-cut-protective-window","title":"ZWO D60 UV IR-Cut Protective Window","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThe \u003cstrong\u003eZWO D60 UV IR-Cut Protective Window\u003c\/strong\u003e is a \u003cstrong\u003e60 mm\u003c\/strong\u003e replacement window for ZWO's large-format cooled cameras. It is \u003cstrong\u003e2 mm\u003c\/strong\u003e thick, figured to \u003cstrong\u003e1\/4 λ flatness\u003c\/strong\u003e, and mounts directly in front of the sensor — sealing the cooled sensor chamber against dust and humidity while blocking ultraviolet and infrared outside the visible band.\u003c\/p\u003e\n\u003cp\u003eThis is the window ZWO fits to its \u003cstrong\u003eone-shot-colour\u003c\/strong\u003e full-frame and APS-C cooled bodies. The monochrome equivalents take the AR window instead, for reasons covered below.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThis is a good match if you own an \u003cstrong\u003eASI6200MC Pro, ASI2400MC Pro, or ASI2600MC Pro\/Duo\u003c\/strong\u003e and need to replace a window that is scratched, fogged, or contaminated beyond cleaning.\u003c\/p\u003e\n\u003cp\u003eOn a cooled camera the window matters more than on an uncooled one: it is the seal that keeps the desiccated sensor chamber dry. A compromised window is not just an optical problem — it is a condensation problem.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e60 mm diameter, 2 mm thick:\u003c\/strong\u003e the D60 form factor, sized for ZWO's APS-C and full-frame cooled bodies\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUV IR-cut coating:\u003c\/strong\u003e passes visible light and rejects ultraviolet and infrared — the correct behaviour for a one-shot-colour sensor with no filter in the train\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e1\/4 λ flatness across 60 mm:\u003c\/strong\u003e holding that figure over this aperture is why the substrate is 2 mm rather than 1.1 mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSensor-chamber seal:\u003c\/strong\u003e on a TEC-cooled camera this window is the barrier keeping humidity away from a sensor held well below ambient\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCoated optical glass\u003c\/strong\u003e, supplied as a bare window\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eReplacing a scratched or contaminated window\u003c\/strong\u003e on an ASI6200MC Pro, ASI2400MC Pro, or ASI2600MC Pro\/Duo\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRestoring the sensor-chamber seal\u003c\/strong\u003e on a cooled camera that has begun showing condensation or frosting\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOne-shot-colour deep-sky imaging\u003c\/strong\u003e, where IR-cut at the sensor keeps stars tight and colour honest without consuming a filter slot\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWide-field refractor work\u003c\/strong\u003e, where uncorrected infrared focuses at a different point than visible light and bloats stars\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eCompatibility and Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eCameras shipped with this window:\u003c\/strong\u003e ASI6200MC Pro, ASI2400MC Pro, and ASI2600MC Pro\/Duo\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColour bodies take IR-cut, mono bodies take AR.\u003c\/strong\u003e The ASI6200MM Pro and ASI2600MM Pro\/Duo ship with the D60 AR window instead, because a monochrome camera does its filtering in the filter wheel and an IR-cut at the sensor would be redundant. The ASI071MC Pro also takes the AR window\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDiameter is not interchangeable:\u003c\/strong\u003e D60 fits 60 mm bodies only. ASI1600 \/ ASI294 \/ ASI183 \/ ASI533 take the D32; smaller planetary bodies take the D21 or D25\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNo installation direction:\u003c\/strong\u003e ZWO confirms the window has no preferred orientation\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eReplacement procedure:\u003c\/strong\u003e see ZWO's official guide, \u003ca href=\"https:\/\/i.zwoastro.com\/wp-content\/uploads\/2025\/12\/c36da643469647ac8334179b49aa8b11.pdf\" target=\"_blank\" rel=\"noopener\"\u003eHow to Replace the Camera Protective Window\u003c\/a\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMechanical part only\u003c\/strong\u003e — no electronic function, no camera communication\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eImportant Limitations\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eThis is the highest-risk window in the range to replace yourself.\u003c\/strong\u003e These are cooled, desiccated cameras — opening the sensor chamber exposes a large sensor to dust and room humidity, and any moisture sealed inside will condense the moment the TEC runs. Check your desiccant before reassembling\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIt will defeat infrared imaging.\u003c\/strong\u003e If you shoot IR-pass work, this window blocks exactly the light you want. Use the D60 AR instead\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNot a threaded filter.\u003c\/strong\u003e It is a bare optical window that only works installed inside the camera body\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNot a light-pollution or narrowband filter\u003c\/strong\u003e — it cuts UV and IR only\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFits 60 mm bodies only.\u003c\/strong\u003e Check your camera against the list above before ordering\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSold as a single window.\u003c\/strong\u003e No tools, gaskets, desiccant, or retaining ring included\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eWhich cameras use the D60 UV IR-cut window?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe ASI6200MC Pro, ASI2400MC Pro, and ASI2600MC Pro\/Duo — ZWO's one-shot-colour large-format cooled bodies.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhy does my ASI2600MM Pro have a different window?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eBecause it is monochrome. Mono cameras filter in the filter wheel, so an IR-cut coating at the sensor would be redundant and would block narrowband and infrared work. ZWO fits the D60 AR window to the mono bodies instead.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat is the difference between the AR window and the UV IR-cut window?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe AR window is anti-reflective coated but optically clear and passes UV and IR. This one blocks both. ZWO confirms the AR window does not cut UV.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDo I still need a UV\/IR-cut filter in my imaging train?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNot for that purpose. With this window fitted the IR-cut happens at the sensor, which frees a slot in your drawer or wheel.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDoes the window have to face a particular direction?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNo. ZWO confirms there is no specific installation direction.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhy is this window 2 mm thick when the D21 and D25 are 1.1 mm?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eHolding 1\/4 λ flatness across a 60 mm aperture takes a thicker substrate than across 21 mm. Thin glass at this diameter would not stay flat.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eMy cooled camera is frosting up. Is the window the cause?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eIt can be, if the seal is compromised — but exhausted desiccant is the more common culprit. Check and bake or replace the desiccant first before opening the sensor chamber.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eIs this good for beginners?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNo. Replacing a window on a large cooled camera is the least forgiving job in this range. If you are not equipped to work clean and manage desiccant, have it done.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eIn short: a 60 mm × 2 mm UV IR-cut window at 1\/4 λ flatness — the factory part for the ASI6200MC Pro, ASI2400MC Pro, and ASI2600MC Pro\/Duo. Colour bodies take this; mono bodies take the D60 AR. Fitting it means opening a cooled, desiccated chamber, so treat the desiccant as part of the job.\u003c\/p\u003e","brand":"ZWO","offers":[{"title":"Default Title","offer_id":53804480790639,"sku":"D60-2-IRCUT","price":75.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/426474105bc9afcb1261044235a281b3-1_fa6aff16-5e86-4ebc-9e24-bd41bfd085a6.jpg?v=1784083651"},{"product_id":"zwo-d60-ar-protective-window","title":"ZWO D60 AR Protective Window","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThe \u003cstrong\u003eZWO D60 AR Protective Window\u003c\/strong\u003e is a \u003cstrong\u003e60 mm\u003c\/strong\u003e replacement window for ZWO's large-format cooled cameras. It is \u003cstrong\u003e2 mm\u003c\/strong\u003e thick, figured to \u003cstrong\u003e1\/4 λ flatness\u003c\/strong\u003e, and carries an \u003cstrong\u003eanti-reflective coating\u003c\/strong\u003e. It mounts directly in front of the sensor and seals the cooled sensor chamber against dust and humidity.\u003c\/p\u003e\n\u003cp\u003eAn AR window is optically clear — it reduces surface reflections but does \u003cstrong\u003enot\u003c\/strong\u003e block ultraviolet or infrared. That is deliberate on these bodies, and the reason is worth understanding before you order.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThis is a good match if you own an \u003cstrong\u003eASI6200MM Pro, ASI2600MM Pro\/Duo, or ASI071MC Pro\u003c\/strong\u003e and need to replace a window that is scratched, fogged, or contaminated beyond cleaning.\u003c\/p\u003e\n\u003cp\u003eIf you run a \u003cstrong\u003emonochrome camera behind a filter wheel\u003c\/strong\u003e, this is the window you want and the one ZWO fits: your filters already control the passband, and an IR-cut coating at the sensor would only get in the way of narrowband and infrared work.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e60 mm diameter, 2 mm thick:\u003c\/strong\u003e the D60 form factor, sized for ZWO's APS-C and full-frame cooled bodies\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAnti-reflective coating:\u003c\/strong\u003e reduces reflection losses and internal glare at the window surfaces — worth having on a large sensor where bright-star halos are most visible\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOptically clear:\u003c\/strong\u003e passes UV and IR straight through, leaving all wavelength control to your filter wheel\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e1\/4 λ flatness across 60 mm:\u003c\/strong\u003e holding that figure over this aperture is why the substrate is 2 mm rather than 1.1 mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSensor-chamber seal:\u003c\/strong\u003e on a TEC-cooled camera this window is the barrier keeping humidity away from a sensor held well below ambient\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eReplacing a scratched or contaminated window\u003c\/strong\u003e on an ASI6200MM Pro, ASI2600MM Pro\/Duo, or ASI071MC Pro\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLRGB and narrowband monochrome imaging\u003c\/strong\u003e, where the filter wheel does the filtering and the window should stay neutral\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePhotometry and scientific imaging\u003c\/strong\u003e, where you want no unnecessary coating shaping the passband\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInfrared imaging\u003c\/strong\u003e, which an IR-cut window would defeat outright\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRestoring the sensor-chamber seal\u003c\/strong\u003e on a cooled camera showing condensation or frosting\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eCompatibility and Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eCameras shipped with this window:\u003c\/strong\u003e ASI6200MM Pro, ASI2600MM Pro\/Duo, and ASI071MC Pro\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMono bodies take AR, colour bodies take IR-cut\u003c\/strong\u003e — with one exception. The ASI071MC Pro is a one-shot-colour camera that ZWO nonetheless fits with the AR window, so do not infer your window type from mono-versus-colour alone. Check the list\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWant IR-cut instead?\u003c\/strong\u003e Fit the D60 UV IR-Cut window — same diameter and thickness, different coating. That is the factory part on the ASI6200MC Pro, ASI2400MC Pro, and ASI2600MC Pro\/Duo\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDiameter is not interchangeable:\u003c\/strong\u003e D60 fits 60 mm bodies only. ASI1600 \/ ASI294 \/ ASI183 \/ ASI533 take the D32; smaller planetary bodies take the D21 or D25\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNo installation direction:\u003c\/strong\u003e ZWO confirms the window has no preferred orientation, so the coating works either way round\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eReplacement procedure:\u003c\/strong\u003e see ZWO's official guide, \u003ca href=\"https:\/\/i.zwoastro.com\/wp-content\/uploads\/2025\/12\/c36da643469647ac8334179b49aa8b11.pdf\" target=\"_blank\" rel=\"noopener\"\u003eHow to Replace the Camera Protective Window\u003c\/a\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMechanical part only\u003c\/strong\u003e — no electronic function, no camera communication\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eImportant Limitations\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eThis window does not cut UV or IR.\u003c\/strong\u003e ZWO states that plainly. On the ASI071MC Pro — a colour camera — that means you need a UV\/IR-cut filter in your imaging train, or infrared will focus at a different point than visible light and bloat your stars\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThis is the highest-risk window in the range to replace yourself.\u003c\/strong\u003e These are cooled, desiccated cameras — opening the sensor chamber exposes a large sensor to dust and room humidity, and any moisture sealed inside will condense the moment the TEC runs. Check your desiccant before reassembling\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNot a threaded filter.\u003c\/strong\u003e It is a bare optical window that only works installed inside the camera body\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFits 60 mm bodies only.\u003c\/strong\u003e Check your camera against the list above before ordering\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSold as a single window.\u003c\/strong\u003e No tools, gaskets, desiccant, or retaining ring included\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eWhich cameras use the D60 AR window?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe ASI6200MM Pro, ASI2600MM Pro\/Duo, and ASI071MC Pro.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhy does a monochrome camera use an AR window instead of IR-cut?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eBecause a mono camera filters in the filter wheel. An IR-cut coating at the sensor would be redundant for LRGB work and would block narrowband and infrared imaging outright. Leaving the window neutral keeps every option open.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eMy ASI071MC Pro is a colour camera — why does it have the AR window?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eIt is the exception in the D60 range. ZWO fits it with the AR window, so if you image with it and want IR-cut behaviour, carry a UV\/IR-cut filter in your train.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat is the difference between the AR window and the UV IR-cut window?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe AR window is anti-reflective coated but optically clear and passes UV and IR. The UV IR-cut window blocks both. ZWO confirms the AR window does not cut UV.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDoes the window have to face a particular direction?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNo. ZWO confirms there is no specific installation direction.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhy is this window 2 mm thick when the D21 and D25 are 1.1 mm?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eHolding 1\/4 λ flatness across a 60 mm aperture takes a thicker substrate than across 21 mm. Thin glass at this diameter would not stay flat.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eMy cooled camera is frosting up. Is the window the cause?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eIt can be, if the seal is compromised — but exhausted desiccant is the more common culprit. Check and bake or replace the desiccant before opening the sensor chamber.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eIs this good for beginners?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNo. Replacing a window on a large cooled camera is the least forgiving job in this range. If you are not equipped to work clean and manage desiccant, have it done.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eIn short: a 60 mm × 2 mm anti-reflective window at 1\/4 λ flatness — the factory part for the ASI6200MM Pro, ASI2600MM Pro\/Duo, and ASI071MC Pro. It stays optically neutral so your filter wheel does the filtering. It does not cut UV or IR, which matters if you run the colour ASI071MC Pro.\u003c\/p\u003e","brand":"ZWO","offers":[{"title":"Default Title","offer_id":53804505301103,"sku":"D60-2-AR","price":62.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/f8fc754efe2799ca917eee21d7350efd_f95065e3-4f07-47e6-b6c5-1ae4b917224b.jpg?v=1784083701"},{"product_id":"zwo-ha-7nm-narrowband-filter","title":"ZWO H-alpha 7nm Narrowband Filter","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThe \u003cstrong\u003eZWO H-alpha 7nm Narrowband Filter\u003c\/strong\u003e passes a \u003cstrong\u003e7 nm\u003c\/strong\u003e band centred on the hydrogen-alpha line at \u003cstrong\u003e656 nm\u003c\/strong\u003e and rejects effectively everything else. Peak transmission is around \u003cstrong\u003e90%\u003c\/strong\u003e, off-band rejection is \u003cstrong\u003eOD3 (below 0.1%)\u003c\/strong\u003e, and infrared from \u003cstrong\u003e700–1100 nm is cut\u003c\/strong\u003e. Every size is polished to \u003cstrong\u003e1\/4 wavefront on both surfaces\u003c\/strong\u003e.\u003c\/p\u003e\n\u003cp\u003eAvailable in \u003cstrong\u003ethree sizes — 1.25\" mounted, 36 mm unmounted, and 2\" mounted\u003c\/strong\u003e. Each is a \u003cstrong\u003esingle filter\u003c\/strong\u003e, not a set. Which one you need is decided by your sensor, not your telescope — see the sizing guidance below before ordering.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eChoosing the Right Size\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThis is the only decision that really matters here, and it is the one most often got wrong. \u003cstrong\u003eA filter too small for your sensor vignettes the corners, and no amount of processing recovers it\u003c\/strong\u003e — the cell wall is a physical obstruction.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e1.25\" mounted — for sensors up to about 4\/3\":\u003c\/strong\u003e ASI1600, ASI294, ASI533 and similar. Threaded cell, fits 1.25\" filter wheels and any standard 1.25\" thread. 1.9 mm glass. \u003cstrong\u003eWill vignette APS-C and full-frame\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e36 mm unmounted — for APS-C and smaller:\u003c\/strong\u003e ASI2600MM, ASI294MM and similar. Bare glass, no cell and no thread, so the full 36 mm is clear aperture. Fits the ZWO 36 mm EFW (7×36 mm). 2 mm glass. \u003cstrong\u003eWill not cover full-frame\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e2\" mounted — for sensors up to full-frame:\u003c\/strong\u003e ASI6200MM, ASI2400 and similar. Threaded cell, fits 2\" filter wheels, drawers, and any standard 2\" (M48) thread\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eIf you are between sizes, size up. The cost difference is far smaller than the cost of re-buying.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThis is a good match if you image \u003cstrong\u003eemission nebulae with a monochrome camera\u003c\/strong\u003e from a light-polluted site. A 7 nm passband rejects mercury vapour, sodium vapour, and atmospheric skyglow almost entirely — which is why narrowband work is productive on nights when broadband imaging is not, including with the Moon up.\u003c\/p\u003e\n\u003cp\u003eIt is also the standard first step \u003cstrong\u003ebeyond LRGB\u003c\/strong\u003e: blending a mono H-alpha channel into RGB data sharpens nebular structure while keeping colour natural. H-alpha is the filter most imagers buy first, because it is where emission nebulae are brightest and where narrowband beats broadband by the widest margin.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e656 nm centre wavelength, 7 nm bandpass:\u003c\/strong\u003e targets the hydrogen-alpha emission line where most nebulae radiate strongest\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFWHM 7 ± 0.5 nm:\u003c\/strong\u003e a tight, specified passband rather than a nominal figure\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eApproximately 90% peak transmission\u003c\/strong\u003e at the H-alpha line, with 80% as the floor\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOD3 off-band blocking:\u003c\/strong\u003e under 0.1% transmission outside the passband — this is what kills light pollution\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIR cut from 700–1100 nm:\u003c\/strong\u003e keeps infrared from bloating stars, so no separate UV\/IR-cut filter is needed behind it\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e1\/4 wavefront both surfaces:\u003c\/strong\u003e fine-polished, so the filter does not degrade star shapes in a converging beam\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThree sizes:\u003c\/strong\u003e 1.25\" mounted (1.9 mm glass), 36 mm unmounted (2 mm), and 2\" mounted\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eEmission nebulae\u003c\/strong\u003e — Orion, Lagoon, Eagle, North America, Rosette\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePlanetary nebulae and supernova remnants\u003c\/strong\u003e — the Ring, Dumbbell, Helix, and the Veil\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSHO \/ Hubble-palette imaging\u003c\/strong\u003e combined with the matching S-II and O-III 7 nm filters\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHa-enhanced LRGB\u003c\/strong\u003e, blending H-alpha into RGB to lift structural detail without shifting colour\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eImaging under moonlight or heavy light pollution\u003c\/strong\u003e, where broadband work is not viable\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eCompatibility and Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMonochrome cameras only.\u003c\/strong\u003e A one-shot-colour camera or DSLR has a Bayer matrix, so only the red-sensitive pixels see H-alpha — you lose most of your resolution and most of your light\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e36 mm is unmounted:\u003c\/strong\u003e no cell and no thread. It cannot be screwed into a filter drawer or nosepiece — it is retained by M2 screws in a filter wheel recess, and those screws ship with the ZWO 36 mm EFW\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e1.25\" and 2\" are mounted:\u003c\/strong\u003e threaded cells that fit filter wheels, drawers, and standard filter threads\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThird-party wheels:\u003c\/strong\u003e ZWO specifies filter thickness between 1.5 mm and 3.0 mm for its wheels\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOrientation:\u003c\/strong\u003e ZWO advises that on the current Mark II filters the \u003cstrong\u003ecoated side should face the telescope\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBackfocus:\u003c\/strong\u003e glass in a converging beam shifts focus by roughly one third of its thickness — about 0.6–0.7 mm here. Include it in your 55 mm sum, and use the same thickness in every wheel slot so focus does not shift between channels\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSold singly.\u003c\/strong\u003e For all three channels, the S-II and O-III filters are separate products, or buy the 2\" SHO set\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eImportant Limitations\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eNot for one-shot-colour cameras or DSLRs.\u003c\/strong\u003e This is a monochrome imaging filter. On a colour sensor the Bayer matrix wastes most of the signal\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSize must match your sensor.\u003c\/strong\u003e 1.25\" vignettes APS-C and full-frame; 36 mm will not cover full-frame. This is a physical obstruction, not a coating issue\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUnmounted 36 mm glass must be handled by the edges.\u003c\/strong\u003e There is no cell protecting the coating, and a fingerprint on a narrowband coating is a real problem\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNarrowband does not brighten nebulae — it raises contrast\u003c\/strong\u003e by darkening the sky. Expect longer sub-exposures, not brighter ones\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNot a general light-pollution filter.\u003c\/strong\u003e It passes one 7 nm band. Stars and galaxies, which emit broadband, largely disappear\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNot for visual observing.\u003c\/strong\u003e A 7 nm H-alpha band is far too dark for the eye\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eA filter wheel and monochrome camera are required\u003c\/strong\u003e and sold separately\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eWhich size do I need?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eMatch it to your sensor, not your telescope. Up to about 4\/3\" (ASI1600, ASI294, ASI533), the 1.25\" is fine. APS-C and smaller (ASI2600MM), the 36 mm unmounted. Up to full-frame (ASI6200MM), the 2\". Buying 1.25\" for an APS-C camera vignettes the corners permanently.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat is the difference between mounted and unmounted?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eA mounted filter sits in a threaded cell you can screw into things. An unmounted filter is bare glass held by screws in a filter wheel. The 36 mm is unmounted precisely because a cell has walls, and walls block the corners of a big sensor.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eIs this good for beginners?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eIt is a sound first narrowband filter if you already have a monochrome camera and a filter wheel. If you image with a one-shot-colour camera, this is not your next purchase — a dual-band filter is.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWill it work with my ASI2600MC or my DSLR?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNot effectively. Those are colour sensors. Only the red pixels respond to H-alpha, so you throw away roughly three quarters of your resolution. Use a mono camera, or a duo-band filter designed for colour sensors.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhy is my H-alpha image so dark?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThat is the filter working. It rejects over 99.9% of the spectrum. Narrowband raises contrast by darkening the background, not by brightening the target — so plan on longer subs.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan I image with the Moon up?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eYes, and that is much of the point. A 7 nm passband rejects moonlight and light pollution well enough that narrowband nights are the ones a broadband imager writes off.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhich way round does it go?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eZWO advises that on the Mark II filters the coated side should face the telescope.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDo I need a UV\/IR-cut filter as well?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNo. This filter cuts 700–1100 nm itself, so infrared will not bloat your stars through it.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDoes it change my backfocus?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eSlightly. Glass shifts focus by roughly a third of its thickness — about 0.6–0.7 mm depending on size. What matters more is using the same thickness across every wheel slot so focus does not jump between channels.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat do I need for the Hubble palette?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eAll three: this H-alpha, plus the S-II 7 nm at 672 nm and the O-III 7 nm at 500 nm. Map them to R, G, and B in processing.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eIs one filter included, or three?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eOne. Each size option is a single H-alpha filter. The S-II and O-III are separate products.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eIn short: a 7 nm H-alpha filter at 656 nm with roughly 90% peak transmission, OD3 blocking, and 1\/4 wavefront polish — the first narrowband filter most mono imagers buy, and the one that makes light-polluted and moonlit nights productive. Pick the size from your sensor: 4\/3\" takes 1.25\", APS-C takes 36 mm, full-frame takes 2\".\u003c\/p\u003e","brand":"ZWO","offers":[{"title":"1.25\" mounted","offer_id":53804730679407,"sku":"Ha7nm1.25","price":164.0,"currency_code":"CAD","in_stock":true},{"title":"36mm unmounted","offer_id":53804730712175,"sku":"Ha7nmD36","price":214.0,"currency_code":"CAD","in_stock":true},{"title":"2\" mounted","offer_id":53804730744943,"sku":"Ha7nmD2","price":316.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/08fd46e15c0f7c733a032a761034763d.webp?v=1784084878"},{"product_id":"zwo-sii-7nm-narrowband-filter","title":"ZWO S-II 7nm Narrowband Filter","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThe \u003cstrong\u003eZWO S-II 7nm Narrowband Filter\u003c\/strong\u003e passes a \u003cstrong\u003e7 nm\u003c\/strong\u003e band centred on the ionised sulphur line at \u003cstrong\u003e672 nm\u003c\/strong\u003e and rejects effectively everything else. Peak transmission is around \u003cstrong\u003e90%\u003c\/strong\u003e, off-band rejection is \u003cstrong\u003eOD3 (below 0.1%)\u003c\/strong\u003e, and infrared from \u003cstrong\u003e700–1100 nm is cut\u003c\/strong\u003e. Every size is polished to \u003cstrong\u003e1\/4 wavefront on both surfaces\u003c\/strong\u003e.\u003c\/p\u003e\n\u003cp\u003eAvailable in \u003cstrong\u003ethree sizes — 1.25\" mounted, 36 mm unmounted, and 2\" mounted\u003c\/strong\u003e. Each is a \u003cstrong\u003esingle filter\u003c\/strong\u003e, not a set. S-II is the third channel of the SHO trio and the faintest of the three, which matters when you plan integration time.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eChoosing the Right Size\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eSize is decided by your sensor, not your telescope. \u003cstrong\u003eA filter too small vignettes the corners, and no amount of processing recovers it\u003c\/strong\u003e — the cell wall is a physical obstruction.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e1.25\" mounted — for sensors up to about 4\/3\":\u003c\/strong\u003e ASI1600, ASI294, ASI533 and similar. Threaded cell, 1.9 mm glass. \u003cstrong\u003eWill vignette APS-C and full-frame\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e36 mm unmounted — for APS-C and smaller:\u003c\/strong\u003e ASI2600MM, ASI294MM and similar. Bare glass, no cell or thread, so the full 36 mm is clear aperture. Fits the ZWO 36 mm EFW (7×36 mm). 2 mm glass. \u003cstrong\u003eWill not cover full-frame\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e2\" mounted — for sensors up to full-frame:\u003c\/strong\u003e ASI6200MM, ASI2400 and similar. Threaded cell, fits 2\" wheels, drawers, and standard M48 threads\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eIf you are between sizes, size up.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThis is a good match if you are \u003cstrong\u003ealready imaging in H-alpha with a monochrome camera\u003c\/strong\u003e and want to complete the SHO set for Hubble-palette work. S-II sits close to H-alpha in the deep red, but nebulae emit far less strongly in it — so it is a filter you add once the workflow is established, not a starting point.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e672 nm centre wavelength, 7 nm bandpass:\u003c\/strong\u003e targets the ionised sulphur emission line\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFWHM 7 ± 0.5 nm:\u003c\/strong\u003e a tight, specified passband\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eApproximately 90% peak transmission\u003c\/strong\u003e at the S-II line\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOD3 off-band blocking:\u003c\/strong\u003e under 0.1% transmission outside the passband\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIR cut from 700–1100 nm:\u003c\/strong\u003e matters more here than on the other channels, since 672 nm sits near the infrared shoulder\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e1\/4 wavefront both surfaces:\u003c\/strong\u003e fine-polished, so star shapes are not degraded\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThree sizes:\u003c\/strong\u003e 1.25\" mounted (1.9 mm glass), 36 mm unmounted (2 mm), and 2\" mounted\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSHO \/ Hubble-palette imaging\u003c\/strong\u003e alongside the H-alpha and O-III 7 nm filters\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSupernova remnants\u003c\/strong\u003e — the Veil and similar, where S-II traces shocked gas\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePlanetary nebulae\u003c\/strong\u003e, where S-II separates ionisation zones that H-alpha alone blends together\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEmission nebulae\u003c\/strong\u003e where you want the full three-channel palette rather than HOO bicolour\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eImaging under moonlight or heavy light pollution\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eCompatibility and Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMonochrome cameras only.\u003c\/strong\u003e On a one-shot-colour sensor the Bayer matrix wastes most of the signal\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e36 mm is unmounted:\u003c\/strong\u003e no cell and no thread. It is retained by M2 screws in a filter wheel recess — those screws ship with the ZWO 36 mm EFW\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e1.25\" and 2\" are mounted:\u003c\/strong\u003e threaded cells that fit filter wheels, drawers, and standard filter threads\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThird-party wheels:\u003c\/strong\u003e ZWO specifies filter thickness between 1.5 mm and 3.0 mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMatch thickness across the wheel\u003c\/strong\u003e so focus does not shift between channels\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOrientation:\u003c\/strong\u003e ZWO advises the \u003cstrong\u003ecoated side should face the telescope\u003c\/strong\u003e on Mark II filters\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBackfocus:\u003c\/strong\u003e glass shifts focus by roughly one third of its thickness — about 0.6–0.7 mm depending on size\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eImportant Limitations\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eS-II is the faintest of the three SHO channels.\u003c\/strong\u003e Expect substantially longer integration than H-alpha for comparable signal. That is astrophysics, not a filter fault\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSize must match your sensor.\u003c\/strong\u003e 1.25\" vignettes APS-C and full-frame; 36 mm will not cover full-frame\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUnmounted 36 mm glass must be handled by the edges\u003c\/strong\u003e — no cell protects the coating\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNot for one-shot-colour cameras or DSLRs\u003c\/strong\u003e — monochrome imaging only\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNot useful on its own.\u003c\/strong\u003e S-II without H-alpha and O-III is one channel of a three-channel palette\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNot for visual observing\u003c\/strong\u003e — a 7 nm band at 672 nm is far too dark for the eye\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eA filter wheel and monochrome camera are required\u003c\/strong\u003e and sold separately\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eWhy is my S-II data so much weaker than my H-alpha?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eBecause nebulae emit far less strongly at 672 nm than at 656 nm. That is normal and expected. Plan on longer total integration in S-II than in H-alpha — many imagers run roughly twice as long.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhich size do I need?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eMatch it to your sensor, not your telescope. Up to about 4\/3\" (ASI1600, ASI294, ASI533), the 1.25\". APS-C and smaller (ASI2600MM), the 36 mm unmounted. Up to full-frame (ASI6200MM), the 2\".\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat is the difference between mounted and unmounted?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eA mounted filter sits in a threaded cell you can screw into things. An unmounted filter is bare glass held by screws in a filter wheel. The 36 mm is unmounted because a cell has walls, and walls block the corners of a big sensor.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDo I need this if I already have H-alpha and O-III?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eOnly if you want the full Hubble palette. HOO bicolour from H-alpha and O-III is a perfectly respectable stopping point, and it costs a lot less integration time.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWill it work with my colour camera or DSLR?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNot effectively. Only the red-sensitive pixels of a Bayer matrix see 672 nm, so you discard most of your resolution and light.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDo I need a UV\/IR-cut filter as well?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNo. This filter cuts 700–1100 nm itself, which matters for S-II because 672 nm sits close to the infrared.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhich way round does it go?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eZWO advises that on the Mark II filters the coated side should face the telescope.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan I image with the Moon up?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eYes. A 7 nm passband rejects moonlight and light pollution well enough to make those nights productive.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eIs this good for beginners?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eIt is not a first filter. Start with H-alpha, learn the mono narrowband workflow, then add O-III and S-II.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eIs one filter included, or three?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eOne. Each size option is a single S-II filter.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eIn short: a 7 nm S-II filter at 672 nm with roughly 90% peak transmission, OD3 blocking, and 1\/4 wavefront polish — the third SHO channel, and the one that needs the most integration time. Pick the size from your sensor: 4\/3\" takes 1.25\", APS-C takes 36 mm, full-frame takes 2\".\u003c\/p\u003e","brand":"ZWO","offers":[{"title":"1.25\" mounted","offer_id":53804739952751,"sku":"SII7nm1.25","price":164.0,"currency_code":"CAD","in_stock":true},{"title":"36mm unmounted","offer_id":53804739985519,"sku":"SII7nmD36","price":214.0,"currency_code":"CAD","in_stock":true},{"title":"2\" mounted","offer_id":53804740018287,"sku":"SII7nmD2","price":316.0,"currency_code":"CAD","in_stock":true}]},{"product_id":"zwo-oiii-7nm-narrowband-filter","title":"ZWO O-III 7nm Narrowband Filter","description":"\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThe \u003cstrong\u003eZWO O-III 7nm Narrowband Filter\u003c\/strong\u003e passes a \u003cstrong\u003e7 nm\u003c\/strong\u003e band centred on the doubly-ionised oxygen line at \u003cstrong\u003e500 nm\u003c\/strong\u003e and rejects effectively everything else. Peak transmission is around \u003cstrong\u003e90%\u003c\/strong\u003e, off-band rejection is \u003cstrong\u003eOD3 (below 0.1%)\u003c\/strong\u003e, and infrared from \u003cstrong\u003e700–1100 nm is cut\u003c\/strong\u003e. Every size is polished to \u003cstrong\u003e1\/4 wavefront on both surfaces\u003c\/strong\u003e.\u003c\/p\u003e\n\u003cp\u003eAvailable in \u003cstrong\u003ethree sizes — 1.25\" mounted, 36 mm unmounted, and 2\" mounted\u003c\/strong\u003e. Each is a \u003cstrong\u003esingle filter\u003c\/strong\u003e, not a set. O-III sits in the blue-green where most CMOS sensors peak, making it the most efficient of the three SHO channels.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eChoosing the Right Size\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eSize is decided by your sensor, not your telescope. \u003cstrong\u003eA filter too small vignettes the corners, and no amount of processing recovers it\u003c\/strong\u003e — the cell wall is a physical obstruction.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e1.25\" mounted — for sensors up to about 4\/3\":\u003c\/strong\u003e ASI1600, ASI294, ASI533 and similar. Threaded cell, 1.9 mm glass. \u003cstrong\u003eWill vignette APS-C and full-frame\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e36 mm unmounted — for APS-C and smaller:\u003c\/strong\u003e ASI2600MM, ASI294MM and similar. Bare glass, no cell or thread, so the full 36 mm is clear aperture. Fits the ZWO 36 mm EFW (7×36 mm). 2 mm glass. \u003cstrong\u003eWill not cover full-frame\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e2\" mounted — for sensors up to full-frame:\u003c\/strong\u003e ASI6200MM, ASI2400 and similar. Threaded cell, fits 2\" wheels, drawers, and standard M48 threads\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eIf you are between sizes, size up.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eThis is a good match if you image \u003cstrong\u003eplanetary nebulae and supernova remnants with a monochrome camera\u003c\/strong\u003e. O-III is where those targets show structure that H-alpha simply does not record — the Veil's filaments and the Helix's inner shell are O-III features.\u003c\/p\u003e\n\u003cp\u003eIt is also the second filter most imagers add after H-alpha, and the partner for HOO bicolour work if you are not ready for the full SHO set.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e500 nm centre wavelength, 7 nm bandpass:\u003c\/strong\u003e targets the major doubly-ionised oxygen emission line\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFWHM 7 ± 0.5 nm:\u003c\/strong\u003e a tight, specified passband\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eApproximately 90% peak transmission\u003c\/strong\u003e at the O-III line\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOD3 off-band blocking:\u003c\/strong\u003e rejects mercury and sodium vapour lighting and atmospheric skyglow\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSits near peak sensor QE:\u003c\/strong\u003e back-illuminated CMOS sensors peak in the blue-green, so O-III photons are captured efficiently\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e1\/4 wavefront both surfaces:\u003c\/strong\u003e fine-polished, so star shapes are not degraded\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThree sizes:\u003c\/strong\u003e 1.25\" mounted (1.9 mm glass), 36 mm unmounted (2 mm), and 2\" mounted\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003ePlanetary nebulae\u003c\/strong\u003e — the Ring, Dumbbell, and Helix, where O-III carries the inner structure\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSupernova remnants\u003c\/strong\u003e — the Veil, whose filamentary detail is largely an O-III signal\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHOO bicolour imaging\u003c\/strong\u003e, mapping H-alpha to red and O-III to green and blue\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSHO \/ Hubble-palette imaging\u003c\/strong\u003e alongside the H-alpha and S-II 7 nm filters\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eImaging under moonlight or heavy light pollution\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eCompatibility and Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMonochrome cameras only.\u003c\/strong\u003e On a one-shot-colour sensor the Bayer matrix wastes most of the signal\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e36 mm is unmounted:\u003c\/strong\u003e no cell and no thread. It is retained by M2 screws in a filter wheel recess — those screws ship with the ZWO 36 mm EFW\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e1.25\" and 2\" are mounted:\u003c\/strong\u003e threaded cells that fit filter wheels, drawers, and standard filter threads\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFast optics shift narrowband passbands.\u003c\/strong\u003e Below roughly f\/4 the steep cone angle blue-shifts the effective centre wavelength of any narrowband filter — O-III is the channel where that shows first\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThird-party wheels:\u003c\/strong\u003e ZWO specifies filter thickness between 1.5 mm and 3.0 mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMatch thickness across the wheel\u003c\/strong\u003e so focus does not shift between channels\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOrientation:\u003c\/strong\u003e ZWO advises the \u003cstrong\u003ecoated side should face the telescope\u003c\/strong\u003e on Mark II filters\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eImportant Limitations\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eNot for visual observing.\u003c\/strong\u003e A 7 nm imaging filter is far darker than the visual O-III filters sold for eyepiece use — do not confuse the two\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSize must match your sensor.\u003c\/strong\u003e 1.25\" vignettes APS-C and full-frame; 36 mm will not cover full-frame\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHalos around bright stars are the classic O-III complaint.\u003c\/strong\u003e ZWO's Mark II filters improved this, but any narrowband filter can halo on a very bright star in the field. Framing helps more than processing\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUnmounted 36 mm glass must be handled by the edges\u003c\/strong\u003e — no cell protects the coating\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNot for one-shot-colour cameras or DSLRs\u003c\/strong\u003e — monochrome imaging only\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNarrowband raises contrast, not brightness.\u003c\/strong\u003e Expect long sub-exposures\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eA filter wheel and monochrome camera are required\u003c\/strong\u003e and sold separately\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eIs this the same as a visual O-III filter?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNo, and this is a common and expensive mix-up. Visual O-III filters for eyepiece use run much wider passbands so there is enough light to see. A 7 nm imaging filter is far too dark for the eye. Buy the visual version if you observe.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhich size do I need?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eMatch it to your sensor, not your telescope. Up to about 4\/3\" (ASI1600, ASI294, ASI533), the 1.25\". APS-C and smaller (ASI2600MM), the 36 mm unmounted. Up to full-frame (ASI6200MM), the 2\".\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat is the difference between mounted and unmounted?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eA mounted filter sits in a threaded cell you can screw into things. An unmounted filter is bare glass held by screws in a filter wheel. The 36 mm is unmounted because a cell has walls, and walls block the corners of a big sensor.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhich do I buy after H-alpha?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eO-III, usually. It gives you HOO bicolour immediately, and it records structure in planetary nebulae and supernova remnants that H-alpha misses entirely.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhy do I get halos around bright stars?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eIt is the classic narrowband O-III artefact. ZWO's Mark II filters reduced it, but a very bright star in the field can still halo. Reframing to move the star out is more effective than trying to fix it later.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWill this work at f\/3?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eWith a caveat. Below about f\/4 the steep light cone shifts a narrowband filter's effective centre wavelength blueward, and O-III is where you notice it first — transmission at the true line drops. It still works; it just works less well than at f\/5 or slower.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWill it work with my colour camera or DSLR?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNot effectively. Only some pixels of a Bayer matrix see 500 nm, so you discard most of your resolution and light.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhich way round does it go?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eZWO advises that on the Mark II filters the coated side should face the telescope.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan I image with the Moon up?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eYes. A 7 nm passband rejects moonlight well enough to make those nights productive.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eIs one filter included, or three?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eOne. Each size option is a single O-III filter.\u003c\/p\u003e\n\n\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp\u003eIn short: a 7 nm O-III filter at 500 nm with roughly 90% peak transmission, OD3 blocking, and 1\/4 wavefront polish — the second narrowband filter most mono imagers buy, and the channel that carries planetary nebulae and supernova remnants. Not a visual O-III filter. Pick the size from your sensor: 4\/3\" takes 1.25\", APS-C takes 36 mm, full-frame takes 2\".\u003c\/p\u003e","brand":"ZWO","offers":[{"title":"1.25\" mounted","offer_id":53804748701807,"sku":"OIII7nm1.25","price":164.0,"currency_code":"CAD","in_stock":true},{"title":"36mm unmounted","offer_id":53804748734575,"sku":"OIII7nmD36","price":214.0,"currency_code":"CAD","in_stock":true},{"title":"2\" mounted","offer_id":53804748767343,"sku":"OIII7nmD2","price":316.0,"currency_code":"CAD","in_stock":true}]}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/collections\/2-LRGB-ZWO__44151.jpg?v=1794339038","url":"https:\/\/ontariotelescope.com\/collections\/black-friday-zwo-filters.oembed","provider":"Ontario Telescope and Accessories","version":"1.0","type":"link"}